U.S. patent application number 10/926036 was filed with the patent office on 2005-02-03 for airbag device.
Invention is credited to Iida, Hitoshi, Yamada, Tadashi, Yamamoto, Tadashi, Yokoyama, Hirohisa.
Application Number | 20050023809 10/926036 |
Document ID | / |
Family ID | 27482599 |
Filed Date | 2005-02-03 |
United States Patent
Application |
20050023809 |
Kind Code |
A1 |
Yamamoto, Tadashi ; et
al. |
February 3, 2005 |
Airbag device
Abstract
An airbag device comprises a folded and housed airbag including:
a vehicle front-facing wall portion having a gas inlet through
which inflating gas can enter; and a passenger-facing wall portion
directly opposite the gas inlet port. In the airbag, there is
arranged a flow regulating cloth. This flow regulating cloth
regulates the inflow of the inflating gas so that the unnecessary
protrusion of the passenger-facing wall portion toward the
passenger is prevented. Moreover, the flow regulating cloth breaks
at a portion made to be easily torn, before the completion of
inflation of the airbag. In other words, the airbag is released
from the regulation of the inflow of the inflating gas before the
completion of inflation.
Inventors: |
Yamamoto, Tadashi;
(Aichi-ken, JP) ; Iida, Hitoshi; (Aichi-ken,
JP) ; Yokoyama, Hirohisa; (Aichi-ken, JP) ;
Yamada, Tadashi; (Aichi-ken, JP) |
Correspondence
Address: |
POSZ & BETHARDS, PLC
11250 ROGER BACON DRIVE
SUITE 10
RESTON
VA
20190
US
|
Family ID: |
27482599 |
Appl. No.: |
10/926036 |
Filed: |
August 26, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10926036 |
Aug 26, 2004 |
|
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10253504 |
Sep 25, 2002 |
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Current U.S.
Class: |
280/731 |
Current CPC
Class: |
B60R 21/2338 20130101;
B60R 21/2346 20130101; B60R 21/231 20130101; B60R 2021/23382
20130101 |
Class at
Publication: |
280/731 |
International
Class: |
B60R 021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2001 |
JP |
2001-303127 |
Feb 6, 2002 |
JP |
2002-30172 |
Feb 8, 2002 |
JP |
2002-32182 |
Feb 8, 2002 |
JP |
2002-32188 |
Claims
1-5. (Canceled)
6. An airbag device comprising a folded and housed airbag including
a vehicle front-facing wall portion and a passenger-facing wall
portion, wherein said vehicle front-facing wall portion includes a
gas inlet port through which inflating gas can flow, wherein said
passenger-facing wall portion is arranged directly opposite to said
gas inlet port wherein while said airbag is inflated the inflow of
the inflating gas is regulated so that said passenger-facing wall
portion is prevented from unnecessarily protruding toward a
passenger, wherein the regulation of the flow of the inflating gas
into said airbag is ended before the completion of inflation of
said airbag, wherein said airbag has a flow regulating member
arranged therein and having such flexibility as can regulate the
flow of said inflating gas, wherein the regulation of the flow of
said inflating gas is ended by the breakage of said flow regulating
member, wherein said flow regulating member includes a vehicle
front-facing joint portion joining the vehicle front-facing wall
portion at the gas inlet port periphery joining passenger-facing
wall portion, so as to connect vehicle front-facing wall portion at
the gas inlet port periphery and said passenger-facing wall
portion, wherein a portion of said flow regulating member between
said vehicle front-facing joint portion and said passenger-facing
joint portion is broken before the completion of inflation of said
airbag, and wherein said flow regulating member is formed of one
sheet of fabric material and is so arranged in said airbag as to
cover the gas inlet port of said vehicle front-facing wall
portion.
7. (Canceled)
8. (Canceled)
9. An airbag device for a steering wheel comprising an airbag
including a gas inlet port through which an inflating gas can
enter, the airbag being folded and housed, wherein said airbag
includes: an airbag body formed by joining the circumferential
edges of a vehicle front-facing wall portion having said gas inlet
port and a passenger-facing wall portion directly opposite said gas
inlet port, to each other; and a flow regulating member arranged in
said airbag body and having flexibility for regulating the inflow
direction of the inflating gas into said airbag body, wherein said
flow regulating member can regulate the inflating gas to flow into
said airbag body in two directions symmetric with respect to said
gas inlet port, wherein said airbag is laid flat superposing said
vehicle front-facing wall portion and said passenger-facing wall
portion and then folded through at least two stages and then is
housed, wherein at the first stage, said airbag is folded with
creases in the regulating direction of said inflating gas, so that
the portions by the two edges extending furthest perpendicular to
the regulating direction of said inflating gas approach said gas
inlet port, wherein at said second stage, said airbag folded at
said first stage is so folded that the portions by the two edges
extending furthest along the regulating direction of said inflating
gas may approach said gas inlet port, and wherein said airbag is so
folded in an elongated shape along the regulating direction of said
inflating gas at said first folding stage that the portions by the
two edges of said airbag extending furthest perpendicular to the
regulating direction of said inflating gas are folded over each
other, progressively superposing in a direction generally normal to
the opening face of said gas inlet port.
10. An airbag device according to claim 9, wherein said airbag is
so folded at said second stage that the two edges of the airbag
folded at said first stage extending furthest in the regulating
direction of said inflating gas approach said gas inlet port to
form two folded portions next to each other and lined up along the
regulating direction of said inflating gas.
11. An airbag device comprising an airbag inflated by admitting an
inflating gas and including an outer wall at the completion of
inflation and an auxiliary inflation portion arranged within said
airbag body, wherein said airbag body includes a gas inlet port
through which inflating gas can enter, wherein said auxiliary
inflation portion communicates with said gas inlet port and
inflates to protect a passenger before the completion of inflation
of said airbag body, and wherein said auxiliary inflation portion
includes gas outlet ports for allowing the inflating gas flowing at
the time of inflation to flow out to said airbag body and is
constructed to end its inflated state by breaking at a portion
removed from the outer wall of said airbag body before the
completion of inflation of said airbag body.
12. An airbag device according to claim 11, wherein the auxiliary
inflation portion of said airbag is such a flow regulating member
as can control the outflow direction of the inflating gas from said
gas outlet ports into said airbag body so as to prevent said airbag
body from protruding toward the passenger at the beginning of
inflation.
13. An airbag device according to claim 11, wherein the outer wall
of said airbag body includes a vehicle front-facing wall portion
having said gas inlet port, and a passenger-facing wall portion
directly opposite said gas inlet port, wherein the auxiliary
inflation portion of said airbag is joined to said passenger-facing
wall portion and can regulate the spacing distance of said
passenger-facing wall portion from said gas inlet port so as to
prevent the protrusion of said airbag body toward the passenger at
the beginning of inflation, and wherein the regulation of said
spacing distance is ended by the breakage of said auxiliary
inflation portion, thereby allowing completion of the inflation of
said airbag body.
14. An airbag device according to claim 13, wherein the auxiliary
inflation portion of said airbag is formed into such a cylindrical
shape with a circumferential wall portion in which are arranged
said gas outlet ports, the circumferential wall portion extending
from the periphery of the gas inlet port of said vehicle
front-facing wall portion to the portion of the passenger-facing
wall portion directly facing said gas inlet port, wherein the edge
of said circumferential wall portion toward the passenger-facing
wall portion is joined to said passenger-facing wall portion, and
wherein said portion of said passenger-facing wall portion directly
opposite the gas inlet port is the ceiling wall portion of said
auxiliary inflation portion.
15. An airbag device according to claim 14, wherein said
circumferential wall portion is formed so that the annular line of
the joint portion joining the passenger-facing wall portion is
further from the axis of the gas inlet port than the that of the
joint portion joining said vehicle front-facing wall portion.
16. An airbag device according to claim 13, wherein said airbag
includes tethers for regulating the distance of said
passenger-facing wall portion from said gas inlet port at the
completion of inflation of said airbag body.
17. An airbag device comprising a folded and housed airbag
including: a vehicle front-facing wall portion having a gas inlet
port through which inflating gas can enter; and a passenger-facing
wall portion directly opposite said gas inlet port, and which
inflates while the inflow of the inflating gas is regulated so as
to prevent the unnecessary protrusion of said passenger-facing wall
portion toward the passenger, wherein said airbag includes a flow
regulating cloth having flexibility for regulating the flow of said
inflating gas, a first regulating member and a second regulating
member, wherein said first regulating member is joined to said
vehicle front-facing wall portion and said passenger-facing wall
portion so as to regulate the distance from said gas inlet port to
said passenger-facing wall portion directly opposite said gas inlet
port from the beginning to a point midway in inflation, and for
ending the regulation of said distance before completion of
inflation, and wherein said second regulating member is so joined
to said vehicle front-facing wall portion and said passenger-facing
wall portion as to regulate the distance from said gas inlet port
to said passenger-facing wall portion directly opposite said gas
inlet port at the completion of inflation, this distance longer
than the distance of said first regulating member.
18. An airbag device according to claim 17, wherein said airbag is
constructed for the steering wheel of a vehicle, and wherein said
flow regulating cloth regulates the flow of said inflating gas,
when mounted on the vehicle, toward the front and rear of the
vehicle along the plane of the ring of the steering wheel.
19. An airbag device according to claim 17, wherein said first
regulating member ends its regulation of the distance by tearing at
a portion between the joint portion at said vehicle front-facing
wall portion and the joint portion at said passenger-facing wall
portion.
20. An airbag device according to claim 17, wherein said first
regulating member and said second regulating member are formed of
one continuous sheet of regulating fabric material having
flexibility.
21. An airbag device according to claim 17, wherein the flow
regulating cloth of said airbag includes a first flow regulating
cloth for regulating the flow of the inflating gas from the
beginning to a point midway in inflation, and a second flow
regulating cloth for regulating the flow of the inflating gas till
the completion of inflation, wherein said first flow regulating
cloth is said first regulating member, comprising a vehicle
front-facing joint portion joining said vehicle front-facing wall
portion at the periphery of the gas inlet port, and a passenger
side joint portion joining said passenger-facing wall portion, so
as to connect said vehicle front-facing wall portion at the
periphery of the gas inlet port and said passenger-facing wall
portion, and wherein a portion between said vehicle front-facing
joint portion and said passenger side joint portion is broken
before completion of inflation of said airbag.
22. An airbag device according to claim 21, wherein said the first
flow regulating cloth passenger side joint portion is extended, and
wherein said extended portion is joined to said vehicle
front-facing wall portion near said gas inlet port to provide said
second regulating member.
23. An airbag device according to claim 21, further comprising: a
case for housing said airbag folded; and an annular retainer which
can attach said airbag to said case while holding the edge of said
gas inlet port on the inner side of said airbag, wherein said
vehicle front-facing joint portion of said first flow regulating
cloth is joined to said vehicle front-facing wall portion by being
held down by said retainer.
24. An airbag device for a steering wheel comprising an airbag
including a gas inlet port through which inflating gas can enter,
the airbag being folded and housed, wherein said airbag is formed
by joining the circumferential edges of a vehicle front-facing wall
portion having said gas inlet port and a passenger-facing wall
portion directly opposite said gas inlet port, to each other,
wherein said airbag includes an airbag body and a connecting member
arranged in said airbag body, wherein said connecting member is
joined to said passenger-facing wall portion and the periphery of
said gas inlet port, thereby connecting said passenger-facing wall
portion and the periphery of said gas inlet port, wherein said
connecting member can maintain its connected state up to a point
midway in inflation of said airbag and can disconnect before the
completion of inflation of said airbag, and wherein while said
vehicle front-facing wall portion and said passenger-facing wall
portion are laid flat over each other, said connecting member is so
arranged that the center of the joint portion joining the
passenger-facing wall portion is offset from the center of the
joint portion joining the periphery of said gas inlet port.
25. An airbag device for a steering wheel according to claim 24,
wherein said connecting member is arranged such that the center of
the joint portion to said passenger-facing wall portion is offset
forward of the airbag body when mounted on the vehicle, from the
center of the joint portion to the vicinity of the circumferential
edge of said gas inlet port.
26. An airbag device for a steering wheel according to claim 24,
wherein said connecting member is a flow regulating member which
regulates the inflow direction of the inflating gas into said
airbag body so as to prevent the protrusion of said airbag toward
the driver.
27. An airbag device for a steering wheel according to claim 24,
wherein there are arranged in said airbag body a plurality of
tethers for connecting said passenger-facing wall portion and said
vehicle front-facing wall portion to regulate the distance of said
passenger-facing wall portion from said vehicle front-facing wall
portion at the completion of inflation of said airbag.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to the Japanese
patent application of Yamamoto et al., filed Sep. 28, 2001,
No.2001-303127, the Japanese patent application of Yamamoto et al.,
filed Feb. 6, 2002, No.2002-30172, the Japanese patent application
of Yamamoto et al., filed Feb. 8, 2002, No.2002-32182, and the
Japanese patent application of Iida et al., filed Feb. 8, 2002,
No.2002-32188, the entirely of each is hereby incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an airbag device, which
comprises an airbag to be folded and housed and an inflator for
feeding an inflating gas into the airbag.
[0004] 2. Description of Related Art
[0005] In the prior art, the airbag device of this kind is known,
as disclosed in Unexamined Published Japanese Patent Application
No. 149199/1995. The airbag device disclosed is used in the
steering wheel of a vehicle.
[0006] The airbag of this airbag device is provided with two
circular wall portions, i.e., a side facing the engine (facing the
steering wheel) and a wall portion facing the passenger (or the
driver). Moreover, the airbag is formed by sewing the circumference
of the vehicle front-facing wall portion and of the
passenger-facing wall portion to each other. In the vehicle
front-facing wall portion, on the other hand, there is opened a gas
inlet port for admitting an inflating gas from an inflator. In the
vehicle front-facing wall portion, moreover, there is arranged a
flow regulating cloth for clogging the gas inlet port. This flow
regulating cloth regulates the flow of the inflating gas flowing
from the gas inlet port to limit the protruding motion of the
passenger-facing wall portion of the airbag to the passenger (or
the driver) passenger-facing wall portion. This airbag can expand
widely while inflating in the flow direction of the inflating gas
so that it is difficult for it to apply an unnecessary pushing
force to the approaching passenger.
[0007] In the airbag thus constructed, however, the flow of the
inflating gas is regulated from the beginning to the completion of
inflation by the flow regulating cloth. In other words, the flow of
the inflating gas is regulated until just before the completion of
inflation by the flow regulating cloth. In the airbag device having
the aforementioned construction, therefore, there is room for
improvement in shortening the time period from the beginning to the
completion of inflation of the airbag. This is because it is
desired that the inflating gas flow freely from the gas inlet port
into the airbag without being regulated in its flow in the time
period before the completion of inflation of the airbag as to
shorten the time required for the airbag to completely inflate.
[0008] On the other hand, an airbag device for a steering wheel,
having an airbag arranged the flow regulating cloth therein, is
exemplified by International Laid-Open No. WO97/36768. In the
airbag device of this laid-open application, the airbag is so
folded at two stages and housed in the steering wheel so that the
vehicle front-facing wall portion and the driver-facing wall
portion are folded flat so that their edges come toward the gas
inlet port.
[0009] In the airbag device of the above-specified laid-open
application, the flow regulating cloth in the airbag regulates the
inflow of the inflating gas into the airbag body to go in two
directions, i.e., to the front and to the back. In the folding of
the airbag, at the first stage, the left and right side portions of
the airbag are folded to approach the gas inlet port so that the
two folds line up with each other on the left and right. At the
second stage, the respective portions of the edges of the two
folded portions of the first stage projecting forward and located
at the rear are folded so as to also bring these folded portions
closer to the gas inlet port. In short, at the second stage, the
two new folded portions line up with each other at the forward and
rear.
[0010] When the inflating gas flows into the airbag body, moreover,
the airbag is expanded and inflated to complete the inflation while
opening the folds of the second stage and the first stage.
[0011] If the portion of the driver-facing wall portion directly
opposite the gas inlet port is raised at the beginning of inflation
of the airbag by the inflating gas, however, the airbag device thus
constructed is expanded to unfold at the two folded portions of the
second stage. Simultaneously with this, moreover, the two folded
portions of the first stage are also unfolded to separate from each
other. This is because the portions of the airbag on the right and
left sides are folded at the first stage so as to form two folded
portions lined up with each other on the right and left. Moreover,
the unfolding of the two folded portions of the first stage is the
expansion to the left and right, thereby to obstruct the flow
regulating effect of the flow regulating member. Specifically, the
airbag device of the aforementioned construction has room for
improvement in that its effect to regulate the flow of the
inflating gas by the flow regulating cloth arranged in the airbag
body, allowing the airbag to expand widely and quickly in the
regulating direction of the inflating gas.
[0012] In the airbag device, on the other hand, it is has been
proposed that a construction made by inflating an auxiliary
inflation portion arranged in the airbag at the beginning of
inflation in low temperatures would provide protection for the
passenger.
[0013] One known airbag device of this kind is Unexamined Published
Japanese Patent Application No. 8-119052. The disclosed airbag
device is used in the steering wheel of a vehicle.
[0014] In the airbag of this airbag device, the vehicle
front-facing wall portion and the passenger-facing wall portion are
sewn to each other with a rupturable sewing thread so as to
surround the gas inlet port spaced away from the outer edge of the
wall portions. In the portion surrounded by this sewing location,
moreover, there is arranged the auxiliary inflation portion
communicating with the gas inlet port.
[0015] In this airbag, even at a low temperature where the
inflating gas which enters is of a small volume, the passenger (or
the driver) to interfere at the beginning of inflation at the low
temperature can be protected at the beginning of inflation by the
auxiliary inflation portion. This is because inflating gas is made
to flow into the auxiliary inflation portion with a smaller
capacity than that of the airbag body, raising the internal
pressure and so completing the inflation.
[0016] In the airbag of the aforementioned Patent Application,
however, the sewn junction of the vehicle front-facing wall portion
and the passenger-facing wall portion formed on the outer edge of
the auxiliary inflation portion is ruptured when the inflation of
the airbag itself is completed to enlarge the capacity for a
cushioning action. As a result, it is difficult to maintain the
airbag at a predetermined internal pressure and to complete the
inflation. This is because the holes passed by the sewing thread in
the vehicle front-facing wall portion and the passenger-facing wall
portion may be enlarged and leak the inflating gas when the sewing
thread of the sewn portions is ruptured. Especially at low
temperature, the aforementioned problems are serious because it is
difficult to maintain the internal pressure by the inflating gas
can.
[0017] Therefore, the airbag of the Patent Application is provided
at the sewn portion with measures for applying a sealing material
so that the gas may not leak from the sewn portion. Thus, the
airbag production has an increased number of steps of which raises
the cost.
[0018] On the other hand, the airbag device of this kind is desired
to expand and inflate the airbag by regulating the inflow of the
inflating gas so as to suppress the unnecessary protrusion to the
passenger.
[0019] Therefore, there is known an airbag device having a
construction, as disclosed in Unexamined Published Japanese Patent
Application No. 104196/1996. In this airbag device, a flow
regulating cloth for closing the gas inlet port is arranged at the
vehicle front-facing wall portion in the airbag. This flow
regulating cloth regulates the inflow of the inflating gas from the
gas inlet port thereby to suppress the protrusion of the
passenger-facing wall portion in the airbag toward the passenger.
Moreover, the flow regulating cloth is so sewn near its center that
it can be separated from the passenger-facing wall portion.
[0020] In this airbag, from the beginning to a point midway in
inflation, the protrusion of the portion of the passenger-facing
wall portion directly opposite the gas inlet port is prevented from
extending to the passenger by the joining of the flow regulating
cloth to the passenger-facing wall portion. Moreover, the airbag is
enabled to extend its width through the flow of the inflating gas
in the directions as guided by the flow regulating cloth, and then
the junction of the flow regulating cloth to the passenger-facing
wall portion is released, thereby completing the inflation.
[0021] In the airbag of the aforementioned Patent Application,
however, there remains room left for improvement, because the
unnecessary protrusion of the passenger-facing wall portion to the
driver (or the passenger) cannot be avoided after the junction of
the flow regulating cloth to the passenger-facing wall portion is
released. This is because the airbag of the Patent Application is
not provided with a regulating member for regulating the shape at
the completion of inflation.
[0022] In case the airbag device of this kind is arranged in the
steering wheel, moreover, it is desired that the abdomen of the
driver be properly protected when the airbag is expanded and
inflated.
[0023] Therefore, there is known an airbag device having a
construction, as disclosed in Unexamined Published Japanese Utility
Model Application No. 1007/1994. In this airbag device, tethers for
regulating the shape of an airbag at the completion of inflation
are arranged in the airbag. However, the airbag is inflated into an
expanded shape that protrudes away from the engine toward the
abdomen of the driver at the completion of inflation.
[0024] In the airbag device of the aforementioned Utility Model
Application, however, the airbag that has completed its inflation
protrudes away from the engine toward the abdomen of the driver but
at the beginning of inflation of the airbag there is no control of
its shape. Usually in the airbag device of this kind, in order to
protect the driver properly, it is necessary to expand the airbag
to quickly provide a thick cushion immediately after the beginning
of inflation of the airbag between the rear-most (lower) portion of
the steering wheel and the abdomen of the driver. This is because
the steering wheel is positioned in proximity to the driver when
the inflator acts.
SUMMARY OF THE INVENTION
[0025] A first object of the invention is to provide an airbag
device which can suppress the protrusion of an airbag to a
passenger at the beginning of inflation and can shorten the time
period from the beginning to the completion of inflation of the
airbag.
[0026] On the other hand, a second object of the invention is to
provide an airbag device for a steering wheel, which has enhanced
flow regulating effect of the inflating gas by a flow regulating
member arranged in the airbag body so that can its airbag can
widely and quickly be expanded by the inflating gas in the
regulating direction, at the beginning of inflation of the
airbag.
[0027] Moreover, a third object of the invention is to provide an
airbag device provided with an airbag, which can be manufactured
with a smaller number of steps of and at a lower cost while
preventing unnecessary gas leakage from the airbag, even when an
auxiliary inflation portion capable of protecting the passenger at
a low temperature is arranged in the airbag.
[0028] Still further, a fourth object of the invention is to
provide an airbag device which can protect the passenger properly
with an airbag by suppressing the unnecessary protrusion of the
airbag to the passenger from the beginning to the completion of
inflation.
[0029] Furthermore, an object of the invention is to provide an
airbag device for a steering wheel which can inflate a
predetermined portion around the gas inlet port of an airbag
quickly to provide a thick cushion immediately after the beginning
of inflation to protect the driver properly.
[0030] The first object of the invention can be achieved by an
airbag device comprising a folded and housed airbag including a
vehicle front-facing wall portion and a passenger-facing wall
portion,
[0031] wherein the vehicle front-facing wall portion includes a gas
inlet port for allowing the entry flow of an inflating gas,
[0032] wherein the passenger-facing wall portion is arranged to
directly face the gas inlet port,
[0033] wherein during inflation of the airbag the inflow of the
inflating gas is regulated so that expansion of the
passenger-facing wall portion is prevented from unnecessarily
protruding toward a passenger, and
[0034] wherein this regulation of the flow of the inflating gas
into the airbag is released before the completion of inflation.
[0035] When this airbag device is activated, the folded and housed
airbag is expanded by inflation with a gas whose inflow is
regulated. Moreover, the regulation of the flow of the inflating
gas into the airbag is released before the completion of inflation
of the airbag.
[0036] In other words, in the flow of the inflating gas into the
airbag is regulated from the beginning to a point midway in its
inflation. Therefore, the airbag increases in width as it inflates
due to the flow direction of the inflating gas so that unnecessary
protrusion of the passenger-facing wall portion directly opposite
the gas inlet port formed in the vehicle front-facing wall portion
toward the passenger is prevented. Here, it is desired that at this
time the regulated direction of the flow of the inflating gas not
force the passenger-facing wall portion away from the gas inlet
port but to go parallel to surface of the portion of the
passenger-facing wall portion directly opposite the gas inlet
port.
[0037] Before the completion of inflation of the airbag, moreover,
the inflating gas is released from its flow regulation and flows
freely into the airbag so that at the final stage, rapid inflation
is promoted. Therefore, the time period from the beginning to the
completion of inflation can be shortened.
[0038] In the airbag device thus constructed, therefore, it is
possible to suppress the protrusion of the airbag toward the
passenger at the beginning of inflation, and to shorten the time
period from the beginning to the completion of inflation of the
airbag.
[0039] In the airbag device of the aforementioned construction, on
the other hand, it is preferable that the airbag has such tethers
arranged as to regulate the distance from the gas inlet port to the
passenger-facing wall portion at the completion of inflation.
[0040] With this construction of the airbag device, the airbag is
prevented from unnecessarily protruding toward the passenger by the
tethers even at the completion of inflation.
[0041] In the airbag device thus constructed, moreover, it is
preferable that the airbag is preferably constructed for the
steering wheel of a vehicle, and
[0042] that in a vehicle mounted state, the inflating gas is
regulated to flow toward the right and left of the vehicle and in a
direction along the ring portion of the steering wheel.
[0043] In the airbag device thus constructed, the airbag is
inflated from the beginning so as to extend to the forward and
rearward projecting sections of the ring portion of a steering
wheel while being prevented from protruding toward the passenger.
In other words, a portion of the airbag can be arranged from the
beginning of inflation on the rearward projecting section of the
ring portion of the steering wheel. Even if the driver is close to
the ring portion, therefore, the portion of the airbag can be
easily brought into the narrow clearance between the abdomen of the
driver and the rearward projecting section of the ring portion of
the steering wheel.
[0044] In the airbag device of the aforementioned construction,
moreover, it is preferable that the airbag has a flow regulating
member arranged therein and having such a flexibility as can
regulate the flow of the inflating gas, and
[0045] that the regulation of the flow of the inflating gas is
released by the breakage of the flow regulating member.
[0046] With this construction of the airbag device, no useless gas
leakage occurs from the airbag at the completion of inflation. This
is because the regulation of the flow of the inflating gas is
released by the breakage of the flow regulating member having
flexibility and arranged in the airbag. If there is a construction
in which the flow regulating member is sewn to the portion at the
circumference of the airbag by means of the sewing thread so that
the regulation of the gas flow is released by rupturing the sewing
thread, more specifically, the holes in the circumferential wall
passed by the sewing thread may be enlarged. Therefore, the
inflating gas may leak from those holes. If however the flow
regulating member itself is ruptured, however, the holes passed by
the sewing thread in the circumferential wall of the airbag can be
prevented from becoming large even if the flow regulating member is
sewn to the circumferential wall.
[0047] In the airbag device of the aforementioned construction,
still further, it is preferable that the flow regulating member
includes an vehicle front-facing joint portion connected to the gas
inlet port periphery section of the vehicle front-facing wall
portion and a passenger side joint portion to be connected to the
passenger-facing wall portion, so that the flow regulating member
can be connected to the gas inlet port periphery section of the
vehicle front-facing wall portion and the passenger-facing wall
portion, and
[0048] that the portion between the vehicle front-facing joint
portion and the passenger-facing joint portion is broken before the
completion of inflation of the airbag.
[0049] With this construction of the airbag device, the distance
between the gas inlet port periphery section of the vehicle
front-facing wall portion and the passenger-facing wall portion can
be suppressed while inflation of the airbag is still incomplete,
that is, before the breakage between the vehicle front-f acing
joint portion and the passenger side joint portion. This is because
the vehicle front-facing wall portion and the passenger-facing wall
portion are connected by the flow regulating member. From the
beginning to a point midway in inflation, therefore, the airbag can
prevent the passenger-facing wall portion from unnecessarily
protruding toward the passenger by means other than changing the
flow direction of the inflating gas. If the tethers are arranged in
this airbag, it is quite natural that the unnecessary protrusion of
the passenger-facing wall portion to the passenger can be prevented
even at the completion of inflation of the airbag after the flow
regulating member is broken.
[0050] In the airbag device of the aforementioned construction,
still moreover, it is preferable that the flow regulating member is
formed of one band of fabric material and is so arranged in the
airbag as to cover the gas inlet port of the vehicle front-facing
wall portion.
[0051] In the airbag device of the aforementioned construction, on
the other hand, it is acceptable that the flow regulating member is
formed of one band of fabric material and is provided with an
opening to communicate with the gas inlet port and is so arranged
in the airbag that the edge of the opening is arranged on the edge
of the gas inlet port of the vehicle front-facing wall portion.
[0052] With this construction of the airbag device, the airbag,
which can regulate the gas flow and the depth of the airbag at the
beginning of inflation, can be easily manufactured merely by using
one flow regulating member. In other words, an airbag whose depth
and gas flow entry rate at the beginning of inflation is regulated,
can be conveniently manufactured with reduced number of
manufacturing steps and cost. Here, the flow regulating member may
be either so arranged in the airbag as to cover the gas inlet port
of the vehicle front-facing wall portion or formed with an opening
to communicate with the gas inlet port of the vehicle front-facing
wall portion, placed inside the airbag, and arranging the edge of
the flow regulating member opening at the edge of the gas inlet
port. In case the flow regulating member is arranged to cover the
gas inlet port, moreover, it can protect the part of the
passenger-facing wall portion directly opposite the gas inlet port
against the inflating gas.
[0053] Still further, it is preferable that the airbag device
comprises: a case for housing the airbag when folded; and an
annular retainer which can attach the airbag to the case by holding
down the inner side of the airbag at the periphery of the gas inlet
port, and
[0054] that the vehicle front-facing joint portion toward the
engine is joined to the vehicle front-facing wall portion by the
retainer.
[0055] With this construction of the airbag device, the joining of
the vehicle front-facing joint portion in the flow regulating
member to the vehicle front-facing wall portion can be performed
not by using joining means such as sewing but merely by holding it
down with a retainer. Therefore, the vehicle front-facing joint
portion of the flow regulating member can be easily formed.
[0056] The second object of the invention can be achieved with an
airbag device for a steering wheel comprising an airbag including a
gas inlet port through which inflating gas can flow which is folded
and housed,
[0057] wherein the airbag includes:
[0058] an airbag body formed by joining the edges of the vehicle
front-facing wall portion having the gas inlet port and of the
passenger-facing wall portion directly opposite the gas inlet port
to each other; and
[0059] a flow regulating member arranged in the airbag body and
having flexibility for regulating the inflow direction of the
inflating gas into the airbag body,
[0060] wherein the flow regulating member can regulate the
inflating gas to flow into the airbag body in two directions
symmetric with respect to the gas inlet port,
[0061] wherein the airbag is first laid out flat, superposing said
vehicle front-facing wall portion and the passenger-facing wall
portion, and then folded in at least a first stage and a second
stage and then is housed,
[0062] wherein at the first stage, the two points on the edge of
the airbag which are along the line passing through the center and
perpendicular to the regulated direction of the inflating gas is
folded so that the formed creases are parallel to the regulated
direction of the inflating gas, and the folded ends come toward the
gas inlet port,
[0063] wherein at the second stage, the airbag folded at the first
stage is so folded that the two points on the edge along the line
passing through the center and in the regulating direction of the
inflating gas come toward the gas inlet port, and
[0064] wherein the airbag is so folded to be in a shape elongated
along the regulating direction of the inflating gas at the first
folding stage, the two points on the edge of the airbag which are
along the line passing through the center and perpendicular to the
regulated direction of the inflating gas so that the direction of
their overlapping is roughly perpendicular to the opening plane of
said gas inlet port.
[0065] In the airbag device for a steering wheel of the
aforementioned construction, at the beginning of inflation of the
airbag, the portion of the passenger-facing wall portion directly
opposite the gas inlet port is raised by the inflating gas. At the
first folding stage, however, the airbag is folded so that the
areas around the two points on the edge of said airbag which are
along the line passing through the center and perpendicular to the
regulated direction of the inflating gas overlap, thereby to
arrange one folded portion. Therefore, the folded portions of the
first stage are not instantly unfolded but rather the portion of
the passenger-facing wall portion directly opposite the gas inlet
port is raised while keeping the folded state. This is because
friction between the overlapping surfaces by the above two points
causes resistance. Then, the inflating gas flows into the airbag
with its inflow direction regulated by the flow regulating member.
Therefore, the airbag expands at first in the regulating direction
of the inflating gas to unfold the folded portions of the second
stage. After this, moreover, the airbag completes its inflation by
inflating to unfold the folded portions of the first stage. In the
airbag device for the steering wheel thus constructed, more
specifically the folded portions of the second stage are expanded
widely and promptly in the regulated direction of the inflating gas
in the airbag, and then the portions folded perpendicular to the
inflow direction of the inflating gas are expanded to complete the
inflation.
[0066] In the airbag device for the steering wheel of the
aforementioned construction, therefore, the flow regulating effect
of the inflating gas by the flow regulating member arranged in the
airbag body can be enhanced so that the airbag expands widely and
quickly in the regulated direction of the inflating gas, at the
beginning of the inflation of the airbag.
[0067] In the airbag device for the steering wheel of the
aforementioned construction, moreover, it is preferable that the
airbag which has completed the first stage is folded at the second
stage that the two sides of the airbag along the line through the
center in the regulated direction of the inflating gas come toward
the gas inlet port to form two portions folded in the regulated
direction of the inflating gas to be adjacent to each other.
[0068] With this construction of the airbag device for the steering
wheel, if the portions of the passenger-facing wall portion
directly opposite the gas inlet port are raised by the inflating
gas at the beginning of inflation of the airbag with in flowing
gas, the two folded portions of the second stage are expanded away
from each other. This is because the two folded portions were
folded to be adjacent to each other in the regulated direction of
the inflating gas. Moreover, these two folded portions are
individually quickly unfolded without any interference with each
other. Therefore, the folded state of the second stage in the
airbag can be quickly released. As a result, the airbag can be
expanded more quickly.
[0069] The third object of the invention can be achieved by the
airbag device for a steering wheel comprising an airbag inflated by
admitting an inflating gas and including an airbag body which has
an outer circumferential wall when inflation is completed, and an
auxiliary inflation portion arranged in said airbag body,
[0070] wherein the airbag body includes a gas inlet port for
admitting the inflating gas,
[0071] wherein the auxiliary inflation portion communicates with
the gas inlet port and inflates to protect the passenger before the
completion of inflation of the airbag body, and
[0072] wherein the auxiliary inflation portion includes gas outlet
ports for allowing the inflating gas flowing at the time of
inflation to flow out to the airbag body and is constructed to
deflate by rupture at a portion removed from the outer
circumferential wall of the airbag body before the completion of
inflation of the airbag body.
[0073] In the airbag device thus constructed, at the beginning of
action, if the inflating gas flows from the gas inlet port into the
auxiliary inflation portion of the airbag, the auxiliary inflation
portion completes its inflation while flowing a part of the
inflating gas from the gas outlet ports to the airbag body
side.
[0074] If the effective area of the gas outlet ports is set small,
moreover, the flow rate of the inflating gas to flow out to the
airbag body is reduced. Even if the inflating gas flowing in has a
small volume at a low temperature at the beginning of inflation of
the airbag, therefore, internal pressure of the auxiliary inflation
portion can be raised so that cushioning action is retained and the
passenger is protected.
[0075] After this, the auxiliary inflation portion ruptures at
portions removed from the outer circumferential wall of the airbag
body and so deflates. Partially inflated after admitting the
inflating gas from the gas outlet ports, the airbag body further
admits inflating gas smoothly and promptly f to complete the
inflation.
[0076] At the time the auxiliary inflation portion deflates, the
auxiliary inflation portion ruptures at locations removed from the
outer circumferential wall of the airbag body. Even if the
auxiliary inflation portion is joined by sewing to the outer
circumferential wall of the airbag body, therefore, the sewn
portions are not influenced. In other words, the airbag body can
complete its inflation while keeping the holes of the outer
circumferential wall passed by the sewing thread from being
enlarged as in the prior art.
[0077] Therefore, the airbag can be conveniently manufactured
without such work as applying a seal material on the portions
joining the auxiliary inflation portion and the airbag body.
[0078] In the airbag device of the aforementioned construction,
therefore, even if the auxiliary inflation portion capable of
protecting the passenger at a low temperature is arranged in the
airbag, unnecessary gas leakage from the airbag can be prevented
while the airbag can be manufactured in a smaller number of steps
of and at a lower cost as well.
[0079] In the airbag device of the aforementioned construction,
moreover, it is preferable that the auxiliary inflation portion of
the airbag is arranged as such a flow regulating member as can
control the outflow direction of the inflating gas to go out from
the gas outlet ports into the airbag body so as to prevent the
airbag body from protruding to the passenger at the beginning of
inflation.
[0080] With this construction of the airbag device, at the
beginning stage of inflation, the airbag body can admit the
inflating gas from the gas outlet ports of the flow regulating
member serving as the auxiliary inflation portion so that it can
expand widely while suppressing protrusion toward the passenger. At
the beginning of inflation, therefore, the airbag body can be
easily expanded between the passenger and the airbag device even if
the passenger comes close to the airbag device and narrows the
clearance between the passenger and the airbag device. By the
subsequent inflation of the airbag body, moreover, the cushioning
effect can be enhanced so that the airbag body protects the
passenger over a wide area.
[0081] Here, the direction that the auxiliary inflation portion
serving as the flow regulating member feeds the inflating gas to
the airbag body by controlling the flow is preferably not the
direction in which gas would push the portion of the outer
circumferential wall of the airbag body facing the passenger and
directly opposite the gas inlet port away from the gas inlet port
but rather a direction parallel to that portion.
[0082] In the airbag device of the aforementioned construction,
moreover, it is preferable that the outer circumferential wall of
the airbag body includes a vehicle front-facing wall portion having
the gas inlet port, and a passenger-facing wall portion directly
opposite the gas inlet port,
[0083] that the auxiliary inflation portion of the airbag is joined
to the passenger-facing wall portion and can regulate the spacing
distance of the passenger-facing wall portion from the gas inlet
port so as to prevent the protrusion of the airbag body toward the
passenger at the beginning of inflation, and
[0084] that the regulation of the spacing distance is released by
the breakage of the auxiliary inflation portion, after which the
inflation of the airbag body is completed.
[0085] With this construction of the airbag device, before the
completion of inflation of the airbag body, i.e., before deflation
of the auxiliary inflation portion, the distance in the airbag body
between the vehicle front-facing wall portion at the periphery of
the gas inlet port and the passenger-facing wall portion can be
suppressed. Therefore, the airbag body can prevent the
passenger-facing wall portion from unnecessarily protruding toward
the passenger from the beginning to a point midway in inflation
regardless of the flow direction of the inflating gas.
[0086] In the airbag device of the aforementioned construction,
still moreover, it is preferable that the auxiliary inflation
portion of the airbag is formed into a cylindrical shape extending
from the periphery of the gas inlet port of the vehicle
front-facing wall portion to the part of the passenger-facing wall
portion directly opposite the gas inlet port, and whose encircling
wall is provided with gas outlet ports,
[0087] that the edge of the circumferential wall portion on the
side of the passenger-facing wall portion is joined to the
passenger-facing wall portion, and
[0088] that the directly opposing part of the passenger-facing wall
portion is the ceiling portion of the auxiliary inflation
portion.
[0089] In this construction of the airbag device, if the
cylindrical circumferential wall portion extending from the
periphery of the gas inlet port in the vehicle front-facing wall
portion is jointed to the passenger-facing wall portion of the
airbag body, the ceiling wall portion of the auxiliary inflation
portion on the passenger side can be shared with the
passenger-facing wall portion of the airbag body. Therefore, the
components of the auxiliary inflation portion are fewer than the
case in which there is separately provided a member for covering
the opening in the circumferential wall portion of the auxiliary
inflation portion at the end toward the passenger.
[0090] In the airbag device of the aforementioned construction,
moreover, it is preferable that the joint portion joining the
circumferential wall portion to the passenger-facing wall portion
be further toward the outside away from the center axis defined by
the gas inlet port than the joint portion for the vehicle
front-facing wall portion.
[0091] In the case of this construction of the airbag device, the
auxiliary inflation portion inflated shape expands closer to the
ceiling wall portion (on the passenger side) than close to the gas
inlet port. Moreover, the ceiling wall portion side consists of the
passenger-facing wall portion of the airbag body itself so that the
auxiliary inflation portion can protect a passenger who is
interfering with action of the airbag at the beginning of inflation
over a wide area with enhanced cushioning effect.
[0092] With this construction, on the other hand, at the time of
inflation of the auxiliary inflation portion, the gas outlet ports
formed in the circumferential wall portion to feed the inflating
gas to the airbag body are directed to the vehicle front-facing
wall portion. Therefore, while the airbag body inflates protrusion
toward the passenger can be restricted.
[0093] In the airbag device of the aforementioned construction,
moreover, it is preferable that the airbag includes tethers for
regulating the spacing distance of the passenger-facing wall
portion from the gas inlet port at the completion of inflation of
the airbag body.
[0094] In this construction of the airbag device, the airbag body
having completed the inflation is regulated in the spacing distance
of the passenger-facing wall portion from the gas inlet port by the
tethers so that the airbag body can be prevented from unnecessarily
protruding toward the passenger even after the completion of
inflation.
[0095] The fourth object of the invention can be achieved by an
airbag device comprising a folded and housed airbag including: a
vehicle front-facing wall portion having a gas inlet port for
allowing an inflating gas to enter and a passenger-facing wall
portion directly opposite the gas inlet port, inflow of the
inflating gas being regulated as the airbag expands so as to
prevent the unnecessary protrusion of the passenger-facing wall
portion toward the passenger,
[0096] wherein the airbag includes a flow regulating cloth having
flexibility for regulating the flow of the inflating gas, a first
regulating member and a second regulating member,
[0097] wherein the first regulating member is joined to the vehicle
front-facing wall portion and the passenger-facing wall portion so
as to regulate the spacing distance from the gas inlet port to the
passenger-facing wall portion directly opposite the gas inlet port
from the beginning to a point midway in inflation, and so that the
regulation of the spacing distance ends before completion of
inflation, and
[0098] wherein the second regulating member is joined to the
vehicle front-facing wall portion and the passenger-facing wall
portion so as to regulate the spacing distance from the gas inlet
port to the passenger-facing wall portion directly opposite the gas
inlet port at the completion of inflation to a distance longer than
the spacing distance by the first regulating member.
[0099] In the airbag device of this construction, from the
beginning to a point midway in inflation of the airbag, the airbag
is regulated by the first regulating member in the spacing distance
from the gas inlet port to the passenger-facing wall portion
directly opposite the gas inlet port. At this stage, therefore, it
is possible to prevent the airbag from unnecessarily protruding
toward the passenger. At this time, moreover, the inflating gas
admitted is regulated in its flow by the flow regulating cloth, so
that the airbag can be expanded widely while being restricted from
protruding toward the passenger. Therefore, even if the passenger
approaches the airbag device at the beginning of inflation to
narrow the clearance between the passenger and the airbag device,
the airbag can be easily expanded between the passenger and the
airbag device to protect the passenger properly.
[0100] Before the completion of inflation, moreover, the airbag is
released from the regulation of the spacing distance by the first
regulating member, and the spacing distance from the gas inlet port
to the passenger-facing wall portion directly opposite the gas
inlet port is restricted by the second regulating member to be a
larger value than the spacing distance by the first regulating
member. Up until the completion of inflation, therefore, the airbag
can be prevented from unnecessarily protruding to the passenger. At
this time, moreover, the flow of the admitted inflating gas into
the airbag is regulated by the flow regulating cloth. Therefore,
the airbag is expanded as wide as possible to complete the
inflation while being suppressed from protruding to the passenger.
Just before the completion of inflation of the airbag, more
specifically, even if the passenger interferes with the
passenger-facing wall portion, the passenger interferes with the
passenger-facing wall portion after it has widely expanded so that
the airbag does not apply any pushing force to one part of the
passenger and thus protects the passenger.
[0101] In the airbag device of the aforementioned construction,
therefore, the airbag can protect the passenger properly and also
can be prevented from unnecessarily protruding toward the passenger
from the beginning to the completion of inflation.
[0102] In the airbag device of the aforementioned construction, on
the other hand, it is preferable that the airbag is constructed for
the steering wheel of a vehicle, and
[0103] that the flow regulating cloth regulates the flow of the
inflating gas, when mounted on the vehicle, to the most forward and
most rearward positions and along the ring face of the steering
wheel.
[0104] With this construction of the airbag device, the airbag is
inflated from the beginning to extend to the most forward and most
rearward positions and along the ring portion of the steering wheel
while being prevented from protruding to the passenger (driver). In
other words, the airbag can be partially arranged from the
beginning of inflation on the rear side of the ring portion of the
steering wheel. Even if the driver approaches the ring portion,
therefore, one portion of the airbag can be easily inserted into
the narrow clearance between the abdomen of the driver and the rear
side of the ring portion of the steering wheel.
[0105] In the airbag device of the aforementioned construction,
moreover, it is preferable that the first regulating member ends
regulation of the spacing distance by being broken somewhere
between the joint portion joining it to the vehicle front-facing
wall portion and the joint portion joining it to the
passenger-facing wall portion.
[0106] With this construction of the airbag device, no needless gas
leakage occurs from the airbag which has completed the inflation.
This is because the regulation of the spacing distance in the first
regulating member is ended by the breakage of the first regulating
member itself. In the construction in which the first regulating
member is sewn to the portion constructing the circumferential wall
of the airbag by means of sewing thread and in which the regulation
of the spacing distance is released by rupturing the sewing thread,
the holes in the circumferential wall passed by the sewing thread
may be enlarged. Therefore, the inflating gas may leak from those
holes. If the first regulating member itself is ruptured, however,
the holes in the circumferential wall passed by the sewing thread
can be kept from becoming larger even if the first regulating
member is sewn to the circumferential wall of the airbag.
[0107] In the airbag device of the aforementioned construction,
moreover, it is preferable that the first regulating member and the
second regulating member are formed of a continuous regulating
fabric material having flexibility.
[0108] With this construction of the airbag device, the joint of
the regulating members to the vehicle front-facing wall portion and
the passenger-facing wall portion can be shared to reduce the
number of components, as compared with the case in which the first
and second regulating members are separately arranged. Moreover,
the joining operations for the first and second regulating members
can be simplified so that the number of manufacturing steps can be
reduced and the cost can be lowered.
[0109] In the airbag device of the aforementioned structure, still
moreover, it is preferable that the flow regulating cloth of the
airbag includes a first flow regulating cloth for regulating the
flow of the inflating gas from the beginning to a point midway in
inflation, and a second flow regulating cloth for regulating the
flow of the inflating gas till the completion of inflation,
[0110] that the first flow regulating cloth is constructed to be
the first regulating member, including a vehicle front-facing joint
portion toward the engine to be jointed to the vehicle front-facing
wall portion at the periphery of the gas inlet port, and a joint
portion toward the passenger to be jointed to the passenger-facing
wall portion, so as to connect the periphery of the gas inlet port
in the vehicle front-facing wall portion and the passenger-facing
wall portion, and
[0111] that a portion between the engine side joint portion and the
passenger side joint portion is broken before completion of
inflation of the airbag.
[0112] With this construction of the airbag device, for the flow
regulation of the inflating gas, the first flow regulating cloth
can be used from the beginning to a point midway in inflation of
the airbag, and the second flow regulating cloth can be used
subsequently till the completion of inflation of the airbag. In
accordance with the desired depth (i.e., the spacing distance from
the gas inlet port to the passenger-facing wall portion) of the
airbag, the flow direction, the flow rate and the flow velocity of
the inflating gas can be adjusted, and expansion of the airbag
properly over a wide area within the necessary time period of
inflation can be realized. Moreover, the first flow regulating
cloth plays the role of the first regulating member so that there
is minimal increase in the number of components of the airbag even
if the flow regulating is carried out by first and second flow
regulating cloths.
[0113] In the airbag device of the aforementioned construction,
still moreover, it is preferable that the first flow regulating
cloth extends from the passenger side joint portion, and
[0114] that the extended portion is jointed to the vehicle
front-facing wall portion near the gas inlet port to provide the
second regulating member.
[0115] With this construction of the airbag device, the number of
components can be made smaller than that of the case in which the
first and second regulating members are separately arranged, and
the joining of the first and second regulating members can be
simplified. Even if the flow regulating is done by the first and
second flow regulating cloths, therefore, it is possible to
minimize the increase in the number of manufacturing steps and the
rise in the cost.
[0116] Still moreover, it is preferable that the airbag device
further comprises: a case for housing the airbag when folded; and
an annular retainer which can attach the airbag to the case by
holding down the inner side of the airbag at the periphery of the
gas inlet port, and
[0117] that the vehicle front-facing joint portion in the first
flow regulating cloth is jointed to the vehicle front-facing wall
portion while being retained by the retainer.
[0118] With this construction of the airbag device, the joint of
the vehicle front-facing joint portion in the first flow regulating
cloth to the vehicle front-facing wall portion can be done not by
means such as the sewing but merely by retaining it with the
retainer. Therefore, the vehicle front-facing joint portion of the
first flow regulating cloth toward the engine can be easily
formed.
[0119] The fifth object of the invention can be achieved by an
airbag device for a steering wheel comprising an airbag including a
gas inlet port for allowing an inflating gas to enter, this airbag
being folded and housed,
[0120] wherein the airbag is formed by joining the edges of an
vehicle front-facing wall portion having the gas inlet port and a
passenger-facing wall portion directly opposite the gas inlet port,
to each other,
[0121] wherein the airbag includes an airbag body and a connecting
member arranged in the airbag body,
[0122] wherein the connecting member is jointed to the
passenger-facing wall portion and to the periphery of the gas inlet
port to there by connect the passenger-facing wall portion and the
periphery of the gas inlet port,
[0123] wherein the connecting member can maintain this connected
state up to a point midway in the inflation of the airbag and can
end this connected state before the completion of inflation of the
airbag, and
[0124] wherein the connecting member is arranged so that while the
vehicle front-facing wall portion and the passenger-facing wall
portion are expanded flat and superposed, the center of the joint
with the passenger-facing wall portion is offset from the center of
the joint with the periphery of the gas inlet port.
[0125] In the airbag device for the steering wheel of this
construction, in connection with the film length of the vertical
section centered at the gas inlet port in the airbag body, the film
length at the portion of the airbag body in the offset direction
with the joint of the passenger-facing wall portion with the
connecting member as the center is shorter by the length of the
offset than the film length in the opposite direction. In short,
the film length of the portion of the airbag body to the offset
direction from the joint with the passenger-facing wall portion and
the film length to the opposite direction can be elongated by the
length of the offset.
[0126] In the airbag device for the steering wheel of the
aforementioned construction, moreover, at the beginning of
operation, the airbag body begins to inflate with the
passenger-facing wall portion and the periphery of the gas inlet
port connected by the connecting member. Therefore, the airbag can
be so inflated at the beginning as to enlarge the depth of the
portion of the airbag body opposite the offset direction of the
center of the joint of the passenger-facing wall portion with the
connecting member, in which side the film length is enlarged. In
the airbag device for the steering wheel of the aforementioned
construction, more specifically, if the portion of the airbag to be
quickly expanded is made to be on the side of the joint of the
passenger-facing wall portion to the connecting member to the
opposite of the offset direction of this joint, , that portion can
be quickly inflated in the first stage of inflation so that the
cushioning effect of enlarged depth can be obtained.
[0127] In the airbag device for the steering wheel of the
aforementioned construction, moreover, the connecting member
connects the passenger-facing wall portion of the airbag body and
the periphery of the gas inlet port. At the beginning of inflation
of the airbag, therefore, the airbag body is prevented from
protruding toward the driver. In other words, at the beginning of
inflation of the airbag, the inflating gas flows in to the portion
of the airbag body around the gas inlet port. Therefore, inflation
is promoted at the portion around the gas inlet port in the airbag
body. As the inflating gas further flows into the airbag body,
moreover, the connection between the passenger-facing wall portion
and the vicinity of the gas inlet port is broken to allow complete
inflation of the airbag body.
[0128] In the airbag device for the steering wheel of the
aforementioned construction, therefore, the predetermined portion
around of the gas inlet port of the airbag can be inflated quickly
to sufficient depth at the beginning of operation, thereby
protecting the driver properly.
[0129] In the airbag device for the steering wheel of the
aforementioned construction, on the other hand, it is preferable
that the connecting member is arranged such that the center of the
joint with the passenger-facing wall portion is offset toward the
forward edge of the airbag body when mounted on the vehicle the
connecting member extending from the center of the joint portion to
the vicinity of the circumferential edge of the gas inlet port.
[0130] With this construction of the airbag device for the steering
wheel, the length of the film over the airbag body toward the rear
of the vehicle on the side of the joint of the passenger-facing
wall portion and the connecting member opposite to the offset
direction of the joint can be relatively elongated. Therefore, the
airbag can be so inflated at the beginning as to enlarge the depth
the portion of the airbag body toward the rear the vehicle. In
other words, the portion of the airbag body toward the rear of the
vehicle can be inflated faster so as to enlarge the depth there
quickly while however being prevented from protruding to the
driver. As a result, the airbag can be expanded and inflated
quickly enough between the portion of the ring portion of the
steering wheel furthest toward the rear of the vehicle and the
abdomen of the driver to always provide cushioning. At the
beginning of inflation of the airbag, therefore, it is possible to
protect the abdomen of the driver properly.
[0131] In the airbag device for the steering wheel of the
aforementioned construction, moreover, it is preferable that the
connecting member is constructed of a flow regulating member for
regulating the inflow direction of the inflating gas into the
airbag body so as to prevent the protrusion of the airbag to the
driver.
[0132] With this construction of the airbag device for the steering
wheel, the inflating gas discharged from the inflator is guided
into the airbag body while the flow direction is regulated by the
flow regulating member. Therefore, it is possible to further
suppress the protrusion of the airbag body to the driver. Here, the
direction the inflating gas is desired to flow is not the direction
to push the passenger-facing wall portion away from the gas inlet
port but the direction parallel to the passenger-facing wall
portion directly opposite the gas inlet port. In the airbag device
for the steering wheel of this construction, also, the connecting
member consists of a flow regulating member. It is, therefore,
possible not only to regulate the flow direction of the inflating
gas into the airbag body but also to control the depth of the
airbag at the beginning of inflation thereby to regulate the
protrusion of the passenger-facing wall portion to the driver. In
other words, in the airbag device for the steering wheel of the
aforementioned construction, the airbag can be manufactured merely
by arranging the flow regulating member serving as the connecting
member in the airbag body. This makes it unnecessary to arrange the
connecting member and the flow regulating member separately in the
airbag body. As a result, the airbag can be easily manufactured due
to a reduced number of manufacturing steps and so lower the
cost.
[0133] In the airbag device for the steering wheel of this
construction, moreover, it is preferable that there are arranged in
the airbag body a plurality of tethers for connecting the
passenger-facing wall portion and the vehicle front-facing wall
portion to regulate the spacing distance of the passenger-facing
wall portion from the vehicle front-facing wall portion at the
completion of inflation of the airbag.
[0134] With the aforementioned construction of the airbag device
for the steering wheel, the airbag having completed its inflation
is regulated in the spacing distance of the passenger-facing wall
portion from the vehicle front-facing wall portion by the tethers
so that the airbag is regulated from unnecessarily protruding to
the driver even at the completion of inflation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0135] FIG. 1 is a top plan view showing a steering wheel in which
an airbag device according to a first embodiment of the invention
is used;
[0136] FIG. 2 is a schematic section of the steering wheel of the
first embodiment;
[0137] FIG. 3 is a top plan view of the expanded state of an airbag
used in the first embodiment;
[0138] FIG. 4 is a bottom view of the expanded state of the airbag
of the first embodiment;
[0139] FIG. 5 is a schematic section of the expanded state of the
airbag of the first embodiment;
[0140] FIG. 6 is a schematic exploded perspective view showing
component members at the time of manufacturing the airbag of the
first embodiment;
[0141] FIG. 7 is a schematic section showing the vicinity of the
gas inlet port of the airbag of the first embodiment lateral the
vehicle;
[0142] FIGS. 8A to 8D are schematic diagrams showing the steps of
folding the airbag of the first embodiment;
[0143] FIG. 9 is a schematic section showing the inflation starting
state of the airbag in the airbag device of the first embodiment,
the cross section along a line longitudinal to the vehicle;
[0144] FIG. 10 is a schematic section showing the state of the
airbag when inflation is completed in the airbag device of the
first embodiment and taken laterally of the vehicle;
[0145] FIG. 11 is a schematic side view showing the inflating
procedure of the airbag in the airbag device of the first
embodiment;
[0146] FIG. 12 is a top plan view of the expanded state in an
airbag of a second embodiment;
[0147] FIG. 13 is a top plan view of a flow regulating member in
the airbag of the second embodiment;
[0148] FIG. 14 is a schematic section showing the vicinity of an
opening of the airbag of the second embodiment;
[0149] FIG. 15 is a perspective view showing an airbag in an airbag
device of a third embodiment when inflation is completed;
[0150] FIG. 16 is a partially broken top plan view of a flow
regulating cloth to be used in the airbag of the third
embodiment;
[0151] FIGS. 17A and 17B are schematic sections for explaining the
inflating procedure of the airbag in the airbag device of the third
embodiment;
[0152] FIG. 18 is a schematic section of the airbag in the airbag
device of the third embodiment when inflation is completed;
[0153] FIG. 19 is a schematic exploded perspective view showing
component members at the time of manufacturing an airbag in an
airbag device of a fourth embodiment;
[0154] FIG. 20 is a schematic section showing the inflation
starting state of the airbag in the airbag device of the fourth
embodiment, the cross section taken along a line longitudinal to
the vehicle;
[0155] FIG. 21 is a top plan view of the expanded state of an
airbag in an airbag device of a fifth embodiment;
[0156] FIG. 22 is a schematic section of the expanded state in the
airbag of the fifth embodiment;
[0157] FIGS. 23A and 23B are schematic partial sections for
explaining the inflating procedure of the airbag in the airbag
device of the fifth embodiment;
[0158] FIG. 24 is a top plan view of the expanded state of an
airbag in an airbag device of a sixth embodiment;
[0159] FIG. 25 is a schematic section showing the state, in which a
retainer is inserted into the airbag of the sixth embodiment, and
taken longitudinally of the vehicle; and
[0160] FIGS. 26A to 26D are schematic views showing the steps of
folding the airbag of the sixth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0161] The invention will be described below by way of embodiments
shown in the drawings. In addition, the invention is not limited to
the embodiments. All modifications within the requirements of the
claims and equivalents with respect to the requirements should be
included in the scope of the claims.
[0162] One embodiment of the invention will be described with
reference to the accompanying drawings.
[0163] First of all, the description will be made of an airbag
device M1 capable of achieving the first and second objects of the
invention and of airbag devices M2 and M3 capable of the first
object of the invention.
[0164] FIGS. 1 and 2 show the airbag device M1 for a steering wheel
according to the first embodiment of the invention. Here, the
longitudinal, vertical and lateral directions in the first
embodiment are in reference to the steering wheel W which is
mounted on the vehicle, when the vehicle is steered straight
forward, unless otherwise specified. Specifically, the
longitudinal, vertical and lateral directions are defined such that
the vertical direction is the axial direction of the steering shaft
SS (as referred to FIG. 11), to which the steering wheel W is
assembled, such that the longitudinal directions are the
longitudinal directions of the vehicle perpendicular to the axis of
the steering shaft SS, and such that the lateral directions are the
lateral directions of the vehicle perpendicular to the steering
shaft SS.
[0165] The airbag device M1 is arranged over a boss portion B at
the center of the steering wheel W, as shown in FIGS. 1 and 2. The
steering wheel W is provided with a ring portion R to be gripped
when steered, the boss portion B arranged at the center and
connected to the steering shaft SS (as referred to FIG. 11), and
four spoke portions S connecting the boss portion B and the ring
portion R. On the other hand, the steering wheel W is provided with
the airbag device M1 and a steering wheel body 1 as components.
[0166] The steering wheel body 1 comprises a core 2 made of an
aluminum alloy or the like, a coating layer 3 made of a synthetic
resin, and a lower cover 4 made of a synthetic resin and arranged
below the boss portion B. The core 2 is arranged to connect the
individual portions of the ring portion R, the boss portion B and
the spoke portions S. The coating layer 3 covers the core 2
positioned at the ring portion R, the individual spoke portions S
in the vicinity of the ring portion R.
[0167] The airbag device M1 is provided, as shown in FIG. 2, with a
folded airbag 20, an inflator 8 for feeding an inflating gas to the
airbag 20, and a case 10 for housing and holding the airbag 20 and
the inflator 8. The airbag 20 is provided with an airbag body 21
and a flow regulating cloth 36 serving as a flow regulating
member.
[0168] The inflator 8 is provided with a generally cylindrical body
8a and a generally square flange portion 8c protruding from the
outer circumference of the body 8a. The body 8a is provided in its
upper portion with a plurality of gas discharge ports 8b for
discharging the inflating gas. The plural gas discharge ports 8b
are arranged at circumferentially equal spacings in the upper
portion of the body 8a. In other words, the individual gas
discharge ports 8b are arranged so as to radially discharge the
inflating gas from the body 8a. In the flange portion 8c, there are
formed through holes 8d for inserting bolts 6a which are protruded
from a later-described retainer 6.
[0169] This retainer 6 is made of a generally square annular sheet
metal. The retainer 6 is provided at its four corners with the
bolts 6a protruding downward. This retainer 6 holds down the
peripheries of later-described openings 23 and 37a of the airbag
20, and the bolts 6a protrude from the flange portion 8c of the
inflator 8 after passing through the openings 23 and 37a and a
later-described bag holder 11. By fastening nuts 7 on the
individual bolts 6a, moreover, the airbag 20 is mounted on the bag
holder 11 of the case 10 by the retainer 6. Here, this retainer 6
holds the edge of the opening 37a of the flow regulating cloth 36
on the periphery of the opening 23 of the airbag body 21. In other
words, the edge of the opening 37a of the flow regulating cloth 36
is held by the retainer 6 to form the later-described vehicle
front-facing joint portion 38 of the flow regulating cloth 36
toward the engine.
[0170] The case 10 comprises a bag holder 11 made of a sheet metal,
and a pad 15 made of a synthetic resin and acting as the airbag
cover.
[0171] The bag holder 11 comprises a holder plate 12 and a backup
plate 13. The holder plate 12 is formed into a generally
rectangular shape opened upward. The backup plate 13 clamps the pad
15 together with the holder plate 12. These plates 12 and 13 are
provided with insertion holes 12a and 13a, and mounting holes 12b
and 13b arranged around the insertion holes 12a and 13a. These
insertion holes 12a and 13a are for insertion of the body 8a of the
inflator 8 upward. The mounting holes 12b and 13b allow passage of
the bolts 6a of the retainer 6. Moreover, the backup plate 13 is
provided with the not-shown bracket to be connected to the core 2
of the steering wheel body 1.
[0172] The pad 15 is provided with a cover member portion 16
covering the boss portion B, and a sidewall portion 17 protruding
downward in a generally square cylinder shape from the lower face
of the edge of the cover member portion 16. This cover member
portion 16 is provided, in the portion surrounded by the side wall
portion 17, with the two door portions (although not designated)
which open forward and rearward when the airbag 20 is inflated.
Around these doors, the cover material is made thin so that it is
easily torn when pushed by the airbag (not numbered) for opening
the door portions smoothly. The side wall portion 17 is fixed by
the bag holder 11 by being clamped near its lower end by the holder
plate 12 and the backup plate 13 which comprise the bag holder
11.
[0173] Here in the case of the first embodiment, the folded airbag
20 is fixed on its lower face side by the holder plate 12 of the
bag holder 11 and the body 8a of the inflator 8. On the other hand,
the upper face side of the folded airbag 20 is regulated by the
cover member portion 16 and the side wall portion 17 of the pad
15.
[0174] The airbag 20 is provided, as shown in FIGS. 3 to 5, with
the airbag body 21 and the flow regulating cloth 36 acting as the
flow regulating member. The airbag body 21 forms into a bag shape
when the inflating gas enters. The flow regulating cloth 36 is
arranged to regulate the inflow direction of the inflating gas into
the airbag body 21.
[0175] The airbag body 21 is formed of a woven fabric having
flexibility such as polyamide or polyester. The airbag body 21 is
provided with a vehicle front-facing wall portion 22 having a gas
inlet port (or opening) 23,and a passenger-facing wall portion 25
arranged to be directly opposite the gas inlet port 23. The vehicle
front-facing wall portion 22 is positioned on the side of the
steering wheel W when the inflation of the airbag 20 is completed.
The passenger-facing wall portion 25 is moved toward the passenger
when the inflation of the airbag 20 is completed.
[0176] The gas inlet port 23 is a portion for causing the inflating
gas discharged from the gas discharge ports 8b of the inflator 8 to
flow into the airbag 20 by inserting the body 8a of the inflator 8
upward. In the periphery of the gas inlet port 23, on the other
hand, there are formed four mounting holes 24 for inserting the
bolts 6a formed at the retainer 6. Here, the bag holder 11 is
arranged between the periphery of the gas inlet port 23 of the
airbag 20 and the flange portion 8c of the inflator 8. However, the
bag holder 11 is omitted from FIGS. 5, 7, 9 and 10.
[0177] In the first embodiment, moreover, the airbag body 21 is
provided, as shown in FIGS. 6 and 7, so that a circular body side
base cloth 28 comprises the vehicle front-facing wall portion 22
and a circular passenger side base cloth 29 comprises the
passenger-facing wall portion 25, and four reinforcing cloths 30,
31, 32 and 33 sewn to the vehicle front-facing base cloth 28 at the
edge of the gas inlet port 23 opening. At the center of the vehicle
front-facing base cloth 28, there is arranged a circular opening
28a for the gas inlet port 23. The reinforcing cloths 30, 31, 32
and 33 are arranged to enhance the strength of the periphery of the
gas inlet port 23. The number of these reinforcing cloths 30, 31,
32 and 33 to be arranged can be suitably altered according to the
output of the inflator 8. The body side base cloth 28 at the
periphery of the opening 28a is provided with four mounting holes
28b forming the mounting holes 24. In the body side base cloth 28,
moreover, there are formed vent holes 28c, as shown in FIG. 4.
[0178] The reinforcing cloths 30, 32 and 33 are individually formed
into such generally annular shapes, with circular openings near
their centers 30a, 32a and 33a corresponding to the gas inlet port
23, as shown in FIG. 6. In the peripheries of the individual
openings 30a, 32a and 33a, moreover, there are individually formed
mounting holes 30b, 32b and 33b at positions corresponding to the
mounting holes 24.
[0179] The reinforcing cloth 31 is arranged between the reinforcing
cloth 30 and the reinforcing cloth 32. Like the individual
reinforcing cloths 30, 32 and 33, the reinforcing cloth 31 is
provided near its center with a circular opening 31a corresponding
to the gas inlet port 23. In the reinforcing cloth 31 at the
periphery of the opening 31a in, , there are formed mounting holes
31b which correspond to the mounting holes 24 as with the
individual reinforcing cloths 30, 32 and 33. From the edge of the
reinforcing cloth 31, there are extended two band-shaped extension
portions 31c to be connected to the later-described tether portions
43 of the flow regulating cloth 36. The extension portions 31 are
arranged symmetrically to the right and left.
[0180] Tethers 45 for regulating the spacing distance from the gas
inlet port 23 to the portion of the passenger-facing wall portion
25 directly opposite the gas inlet port 23 when the airbag 20 has
completed inflation are formed by the tether portions 43 and the
extension portions 31c, which are connected to each other on the
right and left sides.
[0181] The reinforcing cloths 30 and 31 are sewn to the vehicle
front-facing base cloth 28 at three annular sewing locations 47, 48
and 49 with a sewing thread 53. Moreover, the reinforcing cloths 32
and 33 are sewn together with the reinforcing cloths 30 and 31 to
the body side base cloth 28 at the two sewing locations 47 and
48.
[0182] The flow regulating cloth 36 is made, like the airbag body
21, of a woven fabric having flexibility such as polyamide or
polyester. The flow regulating cloth 36 is provided, as shown in
FIGS. 3 and 6, with a generally disc-shaped flow regulating cloth
body 37 and two band-shaped tether portions 43 and 43 extending
from the right and left sides of the circumference of the flow
regulating cloth body 37. The flow regulating cloth body 37 is
provided with the opening 37a for communicating with the gas inlet
port 23 of the airbag body 21. In the periphery of the opening in
the flow regulating cloth body 37, there are formed mounting holes
37b for through which the individual bolts 6a of the retainer 6 are
passed. The body 8a of the inflator 8 is inserted upward into the
opening 37a.
[0183] Moreover, the flow regulating cloth body 37 is provided with
the vehicle front-facing joint portion 38 to be joined to the
vehicle front-facing wall portion 22 in the vicinity of the gas
inlet port 23 of the, and a passenger-facing joint portion 39 to be
joined to the passenger-facing wall portion 25. By those joint
portions 38 and 39 in the flow regulating cloth body 37, therefore,
the wall portion 22 in the vicinity of the gas inlet port 23 in and
the passenger-facing wall portion 25 are connected. In the case of
the first embodiment, as has been described, the vehicle
front-facing vehicle front-facing joint portion 38 is the whole
periphery of the opening 37a. This whole periphery of the opening
37a is jointed vehicle front-facing joint portion to the vehicle
front-facing wall portion 22, thus serving as the vehicle
front-facing joint portion 38 while it is held down by the retainer
6. In the case of the first embodiment, the passenger side joint
portion 39 is formed at an annular sewing location 50 surrounding
the gas inlet port 23 communicating with the opening 37a. At the
sewing location 50 the joint between the vicinity of the outer edge
of the circular flow regulating cloth body 37 and the
passenger-facing wall portion 25 is formed with these wing thread
53.
[0184] In the portion of the flow regulating cloth body 37 between
the vehicle front-facing joint portion 38 and the passenger-facing
joint portion 39, moreover, there are formed gas outlet ports 40.
These gas outlet ports 40 allow the inflating gas discharged from
the inflator 8 to flow out into the airbag body 21. The gas outlet
ports 40a reopened at the front and rear of the periphery of the
opening 37a into rectangles are curved along the circumferential
edge of the opening 37a into arcuate shapes.
[0185] The flow regulating cloth body 37 breaks at the portion
between the vehicle front-facing joint portion 38 and the
passenger-facing joint portion 39 when the internal pressure of the
airbag body 21 reaches a predetermined level, thus disconnecting
the passenger-facing wall portion 25 and the vehicle front-facing
wall portion 22. In the case of the first embodiment, roughly
arcuate easily torn portions 41 and 41 are arranged between the gas
outlet ports 40 and 40 so as to connect the gas outlet ports 40 and
40. Each easily torn portion 41 is formed by perforating the base
cloth making the flow regulating cloth body 37. These easily torn
portions 41 and 41 are torn when the internal pressure of the
airbag body 21 reaches a predetermined level (about 10 to 20 KPa).
When each easily torn portion 41 is torn, moreover, the passenger
side joint portion 39 and the vehicle front-facing joint portion 38
of the flow regulating cloth body 37 are separated and so
disconnect the passenger-facing wall portion 25 and the vehicle
front-facing wall portion 22.
[0186] The tether portions 43 and 43 are formed into band shapes
and are so extended as to protrude in the right and left directions
from the circumferential edge of the flow regulating cloth body 37.
These tether portions 43 and 43 regulate the inflated shape of the
airbag body 21 by regulating the spacing distance of the
passenger-facing wall portion 25 from the gas inlet port 23 when
the air bag 20 is inflated. Moreover, each tether portion 43 is
connected to the vicinity of the gas inlet port 23 by sewing its
end portion 43a with the sewing thread 53 to the end portion 31d of
the extension portion 31c in the reinforcing cloth 31 which is
closer to the vehicle front-facing wall portion 22.
[0187] Here will be described manufacture of the airbag 20. First,
in the flow regulating cloth 36 the opening 37a, the mounting holes
37b, the gas outlet ports 40 and the easily torn portions 41 are
formed. Then, the flow regulating cloth body 37 is sewn at first to
the passenger-facing base cloth 29 by means of the sewing thread
53. When sewing, the sewing location 50 (on the passenger side
joint portion 39) is annular and on the outer side of the gas
outlet ports 40. Then, the reinforcing cloths 30, 31, 32 and 33 are
sewn to the vehicle front-facing base cloth 28 by means of these
wing thread 53. Here, the openings 28a, 30a, 31a, 32a and 33a are
preformed. At this time, the sewn portions 47, 48 and 49 are formed
into the three annular shapes at the periphery of the gas inlet
port 23. The sewn portion 47 arranged on the inner periphery is
formed between the gas inlet port 23 and the mounting holes 24. The
sewing locations 48 and 49 arranged on the outer periphery are
formed outside the mounting holes 24. Moreover, at the sewing
locations 47 and 48 the reinforcing cloths 30, 31, 32 and 33 are
sewed to the vehicle front-facing base cloth 28. At the sewing
location 49 only the reinforcing cloths 30 and 31 are sewed to the
vehicle front-facing base cloth 28.
[0188] Next, the vehicle front-facing base cloth 28 and the
reinforcing cloths 30, 31, 32 and 33 thus sewn are subjected to
boring for the mounting holes 24. Here, the gas inlet port 23 may
be formed simultaneously with this boring, and the openings 28a,
30a, 31a, 32a and 33a need not be formed before the sewing
operations by forming. Here, the vent holes 28c may be formed
either beforehand or simultaneously with the boring.
[0189] After this, the vehicle front-facing base cloth 28 and the
passenger-facing base cloth 29 are so overlapped that their outer
surfaces face each other, and are sewn together at their edges with
the sewing thread 53. After these o edges are sewn, the airbag body
21 is inverted by using the gas inlet port 23 so that the sewing
lines on the edges do not appear on the outer surface of the airbag
20. After this inversion, moreover, the end portions 31d and 31d of
the extension portions 31c and 31c formed in the reinforcing cloth
31 and the end portions 43a and 43a of the tether portions 43 and
43 formed in the flow regulating cloth 36 are individually pulled
out from the gas inlet port 23. The corresponding edges 31d and 43a
are superposed and sewn together with the sewing thread 53.
Moreover, the edges 43a and 43a of the tether portions 43 and 43
are joined through the extension portion 31c, to periphery of the
gas inlet port 23.
[0190] Then, the airbag device M1 is assembled by using the airbag
20 thus manufactured. First, the airbag 20 is folded. In this
embodiment, the retainer 6 is inserted through the openings 23 and
37a into the airbag 20 and is arranged between the passenger side
base cloth 29 and the flow regulating cloth body 37. With the
individual bolts 6a protruding from the mounting holes 37b and 24,
moreover, the airbag 20 is folded through two steps, i.e.,
longitudinal and lateral folding steps.
[0191] At the first step, specifically, the airbag 20 is spread
out, superposing the passenger-facing base cloth 29 on the vehicle
front-facing base cloth 28, as shown in FIG. 8A. At this time, a
central portion 25a of the passenger-facing wall portion 25 is
arranged opposite the gas inlet port 23. Then, the right and left
side portions 56 and 57 perpendicular to the inflating gas
regulated direction are so folded with longitudinal (front-to-rear)
creases as to approach the gas inlet port 23. In this embodiment,
the airbag 20 is folded with the longitudinal crease near the gas
inlet port 23 so that its right side portion 56 lies on the
passenger side base cloth 29. As shown in FIGS. 8B and 8C,
moreover, the right portion 56 and the left portion 57 are folded
alternately with longitudinal creases to form one folded portion 60
containing the right and left sides both folded into the form of a
bellows, thereby completing the longitudinal folding. In short, the
right portion 56 and the left portion 57 are folded on each other
above the gas inlet port 23, in the direction perpendicular to the
opening plane L of the gas inlet port 23. The longitudinally folded
airbag 59 at the end of this first stage is elongated in the
longitudinal direction, that is, the regulated direction of the
inflating gas.
[0192] Next, the two longitudinal edge side portions 61 and 62 in
the directions of the regulated inflating gas in the airbag 59
folded longitudinally in the first stage are folded with lateral
creases so that they approach the gas inlet port 23. In the case of
the embodiment, the front most portion 61 and the rear most portion
62 are individually folded back to have their edges 61a and 62a
lying on the outside. In short, the front side portion 61 and the
rear side portion 62 are folded so as to form two folded portions
64 and 65 adjacent to each other in the longitudinal direction, as
shown in FIG. 8D. In the case of the embodiment, moreover, the two
folded portions 64 and 65 are folded that they lie on the
passenger-facing wall portion 25. This completes the lateral
folding of the second stage and thereby completes the airbag 20
folding.
[0193] How the folded airbag 20 is housed in the case 10 will now
be described. First of all, the individual bolts 6a of the retainer
6 protruding from the folded airbag 20 are passed through the
individual mounting holes 12b formed in the holder plate 12 of the
bag holder 11, and the airbag 20 is placed on the holder plate
12.
[0194] After this, the pad 15 is placed over the airbag 20 and
retfixed to the holder plate 12. Moreover, the backup plate 13 is
arranged below the holder plate 12, and the pad 15 is held on the
bag holder 11 by clamping its side wall portion 17 between the
holder plate 12 and the backup plate 13. At this time, the
individual bolts 6a of the retainer 6 are passed through the
mounting holes 13b formed in the backup plate 13.
[0195] After this, the body 8a of the inflator 8 is inserted upward
into the insertion holes 12a and 13a of the bag holder 11 and the
openings 23 and 37a. Simultaneously with this, the individual bolts
6a of the retainer 6 are protruded downward from the through holes
8d formed in the flange portion 8c of the inflator 8. After this,
the nuts 7 are fastened on the individual bolts 6a to attach the
airbag 20, the bag holder 11 and the inflator 8 integrally and
thereby complete the assembly of the airbag device M1.
[0196] With the core 2 of the boss portion B of the steering wheel
body 1 being fastened on the steering shaft SS of the vehicle, the
not-shown bracket of the bag holder 11 can be used to mount the
airbag device M1 in the steering wheel W.
[0197] If the inflating gas is discharged from the gas discharge
ports 8b of the inflator body 8a after the steering wheel W is
mounted on the vehicle, the folded airbag 20 ruptures the pad 15 at
the predetermined position and inflates to a large size.
[0198] In the airbag device M1 of the first embodiment at the
beginning of this action, the inflating gas G discharged from the
gas discharge ports 8b of the inflator body 8a is for a time stored
between the passenger-facing wall portion 25 (the passenger side
base cloth 29) and the flow regulating cloth body 37 acting as the
flow regulating member, as shown in FIG. 9. After this, the
inflating gas G is directionally controlled to flow from the gas
outlet ports 40 and 40 formed in the flow regulating cloth body 37
into the rearward and forward portions of the airbag body 21.
[0199] When the inflating gas G flows into the airbag body 21 so
that the internal pressure of the airbag body 21 reaches a
predetermined level, moreover, a predetermined or higher tension is
built up between the passenger-facing joint portion 39 and the
vehicle front-facing joint portion 38 in the flow regulating cloth
body 37 thereby to rupture the easily torn portions 41 and 41.
Thus, the passenger-facing wall portion 25 and the vicinity of the
gas inlet port 23 are disconnected. The inflating gas G discharged
from the gas discharge ports 8b in the body 8a of the inflator 8
then flows radially in all directions from the gas inlet port 23
without being regulated, so that the airbag 20 completes its
inflation, as shown in FIG. 10. At this time, the airbag 20 is
caused end its inflation with the spacing distance of the
passenger-facing wall portion 25 from the gas inlet port 23
regulated by the tethers 45 and 45.
[0200] In the airbag device M1 of the first embodiment here
described, when activated, the folded and housed airbag 20 is
expanded and inflated with the inflow of the inflating gas G being
regulated by the flow regulating cloth body 37 using the flow
regulating cloth 36 as the flow regulating member, and the
regulation of the flow of the inflating gas G into the airbag 20 is
ended before the completion of the inflation of the airbag 20 by
the breakage of the flow regulating cloth body 37.
[0201] In the airbag 20, specifically, the flow of the inflating
gas G is regulated from the beginning to a point midway in
inflation by the flow regulating cloth body 37. Therefore, the
airbag 20 can be inflated widely in the flow directions of the
inflating gas G forward and rearward, thereby suppressing any
unnecessary protrusion of the passenger-facing wall portion 25
toward the passenger (or driver D). Before the completion of
inflation of the airbag 20, moreover, the regulation of the flow of
the inflating gas G into the airbag 20 is released by the rupture
of the flow regulating cloth body 37. Thereafter, the inflating gas
G flows freely into the airbag 20 so that the completion of
inflation of the airbag 20 is promoted. As a result, the time
period from the beginning to the completion of the inflation of the
airbag 20 can be shortened.
[0202] In the airbag device M1 of the first embodiment, therefore,
it is possible to suppress the protrusion of the airbag 20 toward
the passenger D at the beginning of inflation and to shorten the
time period from the beginning to the completion of inflation of
the airbag 20.
[0203] In the case of the first embodiment, moreover, the airbag 20
which has completed inflation is regulated by the tethers 45 and 45
with regard to the distance from the gas inlet port 23 to the
portion of the passenger-facing wall portion 25 directly opposite
the gas inlet port 23. Therefore, the airbag 20 can be prevented
even after the completion of inflation from unnecessarily
protruding toward the passenger D.
[0204] In the case of the first embodiment, on the other hand, the
ring portion R of the steering wheel W is arranged in the plane
normal to the steering shaft SS. Moreover, the airbag 20 regulates
the flow of the inflating gas G toward the rearward and forward
directions perpendicular to the steering shaft SS. As a result, the
flow of the inflating gas G is regulated, when the airbag 20 is
mounted on the vehicle, to the rearward and forward directions of
the vehicle along the plane of the ring portion R of the steering
wheel W. Therefore, the rear portion 20a of the airbag 20 can be
arranged from the beginning of inflation to inflate toward the
rearward portion Rb of the ring portion R of the steering wheel W,
while being suppressed in its protrusion toward the passenger D.
Even if the driver D is close to the ring portion R, as shown in
FIG. 11, the portion 20a of the airbag 20 can easily invade into
the narrow gap between the abdomen portion DB of the driver D and
the rear portion Rb of the ring portion R of the steering wheel
W.
[0205] In the first embodiment, moreover, the regulation of the
flow of the inflating gas G is ended by the breakage of the flow
regulating cloth body 37 itself of the flexible flow regulating
cloth 36 arranged in the airbag 20. Therefore, there occurs no
needless gas leakage from the airbag 20 which has completed
inflation. With the construction in which the flow regulating cloth
is sewn to a portion forming the peripheral wall of the airbag by
using sewing thread so that the regulation of the gas flow is
released by rupturing the sewing thread, the holes of the
peripheral wall which were left by the sewing thread are enlarged.
Therefore, the inflating gas may leak from those holes. In the
first embodiment, however, the ruptures occur at the portion 41 of
the flow regulating cloth body 37 removed from vehicle front-facing
wall portion 22 and the passenger-facing wall portion 25. Even if
the flow regulating cloth body 37 is sewn to the passenger side
base cloth 29 of the airbag 20 as in the passenger side joint
portion 39, therefore, it is possible to prevent the holes of the
base cloth 29, which were left by the sewing thread 53, from
becoming larger.
[0206] In the case of the first embodiment, moreover, the easily
torn portions of the flow regulating cloth body 37 are preformed
easily torn portions 41 comprising prearranged slits. Therefore,
the flow regulating cloth body 37 can be properly torn. Here in the
first embodiment, tearing of the flow regulating cloth body 37
makes use of the tension to be applied to the flow regulating cloth
body 37. By using the heat of the inflating gas G, for example, the
connecting portions between the slits in the easily torn portions
41 may be molten to rupture the flow regulating member.
[0207] In the case of the first embodiment, still moreover, the
flow regulating cloth body 37 with the flow regulating cloth 36 as
the flow regulating member is provided with the vehicle
front-facing joint portion 38 and the passenger-facing joint
portion 39. In addition, the flow regulating cloth body 37 connects
the passenger-facing wall portion 25 and the vehicle front-facing
wall portion 22 at the periphery of the gas inlet port 23 to each
other. Before the completion of inflation of the airbag 20, i.e.,
before the tearing of the easily torn portions 41 between the
vehicle front-facing joint portion 38 and the passenger side joint
portion 39, therefore, the distance between the vehicle
front-facing wall portion 22 at the periphery of the gas inlet port
23 of the and the passenger-facing wall portion 25 can be limited
to a small value. As a result, the airbag 20 can prevent the
passenger-facing wall portion 25 from unnecessarily protruding
toward the passenger D from the beginning to a point midway in
inflation regardless of the flow direction of the inflating gas G.
Because the tethers 45 and 45 are arranged in the airbag 20,
unnecessary protrusion of the passenger-facing wall portion 25
toward the passenger D is prevented, even after completion of the
inflation after the breakage of the flow regulating cloth body
37.
[0208] Here, the extent of protrusion of the airbag 20 (or the
depth of the airbag 20) toward the passenger D at the beginning of
inflation can be adjusted since this is the length between the
vehicle front-facing joint portion 38 and the passenger side joint
portion 39. In case the extent of protrusion at the beginning of
inflation is enlarged, for example, the passenger-facing joint
portion 39 may be brought closer to the outer circumferential edge
of the flow regulating cloth body 37. If the general disc shape of
the flow regulating cloth body 37 is enlarged at this time to bring
the passenger-facing joint portion 39 closer to its outer
circumferential edge, it is possible to enlarge the extent of
protrusion of the airbag 20 more at the beginning of inflation. In
case the extent of protrusion at the beginning of inflation is to
be reduced, on the contrary, the passenger side joint portion 39
may be brought closer to the opening 40 in the case of the first
embodiment.
[0209] In the first embodiment, moreover, the flow regulating cloth
36 serving as the flow regulating member is formed of a single
fabric material extending from the vehicle front-f acing joint
portion 38 to the passenger-facing joint portion 39. Merely by
using the single flow regulating cloth 36, therefore, it is
possible to manufacture an airbag 20 which can regulate not only
the gas flow at the beginning of inflation but also the extent of
protrusion (or the depth of the airbag 20) to the passenger D at
the beginning of inflation. In other words, it is possible to
manufacture such an airbag 20 conveniently with a reduced number of
manufacturing steps and thus lower cost, which can regulate the gas
flow at the beginning of inflation and the extent of protrusion (or
the depth of the airbag 20) toward the passenger D at the beginning
of inflation. If this point however is not a concern, the flow
regulating cloth can of course be formed of two fabrics, a member
on the side of the vehicle front-facing joint portion 38 and a
member on the side of the passenger side joint portion 39.
[0210] In the first embodiment, still moreover, the airbag device
M1 comprises a case 10 for housing the folded airbag 20, and an
annular retainer 6 which can put the airbag 20 in such a state that
it is mountable in the case 10 while holding down the inner side of
the airbag 20 at the periphery of the gas inlet port 23. Moreover,
the vehicle front-facing joint portion 38 of the flow regulating
cloth body 37 is joined to the vehicle front-facing wall portion 22
by the retainer 6. In other words, the vehicle front-facing joint
portion 38 in the flow regulating cloth body 37 can be joined to
the vehicle front-facing wall portion 22 not by using joining means
such as the sewing but merely holding it down with the retainer 6.
It is, therefore, possible to form the vehicle front-facing joint
portion 38 of the flow regulating cloth body 37 easily.
[0211] In the first embodiment, moreover, the tether portions 43
and 43 capable of regulating the shape of the airbag 20 at the time
of inflation completion are integrated with the flow regulating
cloth 36. Therefore, the tethers 45 and 45, which can regulate the
shape of the airbag 20 at the time of inflation completion by
regulating the distance from the gas inlet port 23 to the
passenger-facing wall portion 25, need not be separately attached
to the airbag 20. In other words, the end portions of the tethers
45 can be jointed to the passenger-facing wall portion 25 not by
separately joining the end portions of the tethers 45 toward the
passenger-facing wall portion 25 to the passenger-facing wall
portion 25 but merely by jointing the flow regulating cloth body 37
to the passenger-facing wall portion 25. As a result, the airbag 20
having the tethers 45 and 45 can be manufactured with a reduced
number of manufacturing steps and at lowered cost.
[0212] Especially in the case of the first embodiment, the
reinforcing cloth 31 sewn to the vehicle front-facing wall portion
22 is provided with the extension portions 31c, and the end
portions 43a of each tether portion 43 pointed toward the the
vehicle front-facing wall portion 22 are joined to the vehicle
front-facing wall portion 22 by sewing them to the extension
portions 31c. Even if the passenger-facing joint portion 39 of the
flow regulating cloth 36 is sewn to the passenger-facing wall
portion 25. Even if the reinforcing cloth 31 which is provided with
the extension portions 31c is sewed to the vehicle front-facing
wall portion 22, therefore, the end portions 43a of the tether
portions 43 and the extension portions 31c can be pulled out
through the gas inlet port 23 to the outside of the airbag 20 and
then can be easily sewn to each other. As a result, the tethers 45
can be easily formed.
[0213] Even if the above-specified features are not incorporated,
the end portions 43a of the individual tether portions 43 may be
joined or sewn directly to the vicinity of the outer
circumferential edge of the reinforcing cloth 33 in lieu of forming
the extension portions 31c at the reinforcing cloth 31 which is
closer to the vehicle front-facing wall portion 22. Alternatively,
the tethers 45 may be constructed not by forming the individual
tether portions 43 but by extending the extension portions 31c
further and by jointing or sewing their leading edges to the
passenger-facing wall portion 25.
[0214] In the airbag device M1 of the first embodiment, on the
other hand, the airbag 20 is folded in the first and second stages
so that it can carry out the following actions. At the beginning of
inflation of the airbag 20, specifically, the portion 25a of the
passenger-facing wall portion 25 directly opposite the gas inlet
port 23 is raised by the inflating gas. However, the airbag 20 is
folded in the first stage tin to one folded portion 60 in which the
right portion 56 and the left portion 57 generally perpendicular to
the regulated direction of the inflating gas are superposed on each
other. Therefore, the folded portion 60 at the first step is not
expanded to eliminate the creases but raised together with the
portion 25a of the passenger-facing wall portion 25 directly
opposite the gas inlet port 23, and tends to maintain its folded
state. This is because friction is generated with movement of the
folded portion 60 by the mutual contact of the surfaces of the
folded right and left portions 56 and 57 of the first step, which
constitutes resistance to the unfolding. Then, the inflating gas is
caused by the gas outlet ports 40 and 40 of the flow regulating
cloth 36 to flow in the regulated direction into the airbag 20.
Therefore, the airbag 20 is so expanded at first in the regulated
direction of the inflating gas as to unfold the folded portions 64
and 65 folded in the second stage. After this, the airbag 20 is
inflated to unfold the folded portion 60 of the first stage thereby
to complete the inflation. In the airbag device M1 of the first
embodiment, more specifically, the folded portions 64 and 65 folded
in the second stage are expanded widely and quickly in the
regulated direction of the inflating gas in the airbag 20, and then
the portions 56 and 57 in the right and left directions
perpendicular to the inflow direction for the inflating gas are
expanded to complete the inflation.
[0215] In the airbag device M1 of the first embodiment, therefore,
the flow regulating effect of the inflating gas by the flow
regulating cloth 36 arranged in the airbag body 21 can be enhanced
so that the airbag 20 expands widely and quickly at the beginning
of inflation in the regulated direction of the inflating gas.
[0216] If the area of the passenger-facing wall portion 25 directly
opposite the gas inlet port 23 protrudes a great deal toward the
driver at the time of inflation of the airbag 20, the portions 41
and 41 break to disconnect the passenger-facing wall portion 25 and
the vicinity of the gas inlet port 23. In the airbag 20 in the
airbag device M1 of the first embodiment, however, the portion 25a
of the passenger-facing wall portion 25 directly opposite the gas
inlet port 23 is prevented at the beginning of inflation from
greatly protruding by the folded portion 60 of the first stage.
When the airbag 20 is widely expanded in the regulated direction of
the inflating gas, therefore, the portions 41 and 41 of the flow
regulating cloth 36 are broken. Even if the flow regulating cloth
36 is provided with the easily torn portions 41, these portions 41
are not torn before breakage is necessary.
[0217] In the airbag device M1 of the first embodiment, moreover,
at the beginning of inflation of the airbag 20, the portion 25a of
the passenger-facing wall portion 25 directly opposite the gas
inlet port 23 is raised by the inflating gas when this gas flows
in. Then, the two folded portions 64 and 65 of the second stage are
expanded away from each other. This is because the two folded
portions 64 and 65 are folded toward each other along the regulated
directions of the inflating gas. Thus, these two folded portions 64
and 65 are quickly unfolded without interfering with each other.
Therefore, it is possible to undo the folded state of the second
stage in the airbag 20. As a result, the airbag 20 can be expanded
more quickly.
[0218] In the first embodiment, the body 37 of the flow regulating
cloth 36 is provided with the opening 37a communicating with the
gas inlet port 23, and the periphery of the opening 37a is joined
to the vehicle front-facing wall portion 22. However, an airbag 74
of the airbag device M2 shown in FIGS. 12 to 14 may be constructed
such that a flow regulating cloth body 78 covers the gas inlet port
23.
[0219] This airbag 74 is provided for the steering wheel and
comprises an airbag body 75 and a flow regulating cloth 77 acting
as the flow regulating member for regulating the flow direction of
the inflating gas into the airbag body 75. This airbag body 75 has
a construction similar to that of the airbag body 21 in the
aforementioned airbag 20 so that its description will be simplified
by designating the same individual portions with the same reference
numerals.
[0220] The flow regulating cloth 77 is provided, as shown in FIG.
13, with the generally disc-shaped flow regulating cloth body 78
and band-shaped tether portions 84 and 84 formed to protrude from
the edge of the body 78 at the right and left. The flow regulating
cloth body 78 is provided with an annular passenger-facing joint
portion 79 arranged near the flow regulating cloth body's outer
edge. The passenger-facing joint portion 79 is joined to the
passenger-facing wall portion 25 by sewing it to the passenger side
base cloth 28 comprising the passenger-facing wall portion 25. In
the flow regulating cloth body 78, moreover, connecting member
portions 80 formed to protrude outward from the edge are arranged
at four locations radially at equal intervals. In each of the
connecting member portions 80, there is formed a mounting hole 80a
through which the bolt 6a of the retainer 6 passes. In the airbag
74 of the embodiment, as shown in FIG. 14, the retainer 6 is
arranged on the upper sides of the connecting member portions 80.
By mounting and fixing the connecting member portions 80 as well as
the vehicle front-facing wall portion 22 on the bag holder 11 by
means of the retainer 6, moreover, the flow regulating cloth body
78 is joined to the vehicle front-facing wall portion 22 at the
periphery of the gas inlet port 23. In other words, the individual
connecting member portions 80 comprise the vehicle front-facing
joint portion 80 which is retained by the retainer 6 and jointed to
the vehicle front-facing wall portion 22. Moreover, the inner
portions of the individual connecting member portions 80 in the
flow regulating cloth body 78 cover the gas inlet port 23 and cover
the upper face side of the inflator body 8a when the inflator 8 is
mounted and fixed. In the boundaries between the individual
connecting member portions 80 and the flow regulating cloth body
78, moreover, there are arranged easily torn portions 82 which are
constructed by forming slits or perforations, as shown in FIG. 13.
The tether portions 84 and 84 are sewn at their end portions, as
the tether portions 43 in the aforementioned flow regulating cloth
36, to the end portions 31d and 31d of the extension portions 31c
and 31c in the reinforcing cloth 31.
[0221] In the airbag device M2 using the airbag 74 thus
constructed, the upper side of the inflator body 8a is covered with
the body 78 of the flow regulating cloth 77, and the
passenger-facing wall portion 25 is arranged in the vicinity of the
inflator 8 by sewing the passenger side base cloth 29 and the body
78. As a result, the inflating gas G flows, when discharged from
the gas discharge ports 8b of the inflator body 8a, from the body
78 along the passenger side base cloth 29 into the airbag body 75,
as shown in FIG. 14. When the internal pressure of the airbag body
75 reaches a predetermined level, moreover, the individual easily
torn portions 82 formed between the individual connecting member
portions 80 and the body 78 are torn, which disconnects the
passenger-facing wall portion 25 and the periphery of the gas inlet
port 23, and the airbag body 75 then completes its inflation. In
other words, even with the airbag 74 being thus constructed, too,
the inflow direction of the inflating gas G can be controlled by
the single flow regulating cloth 77, and the depth of the airbag 74
at the beginning of inflation can be controlled to regulate the
protrusion of the passenger side base cloth 29 toward the passenger
by the single flow regulating cloth 77. Moreover, the airbag 74 is
regulated in shape of inflation completion by the tether portions
84 so that the protrusion of the passenger side base cloth 29
toward the passenger can be regulated even when inflation is
completed.
[0222] In this airbag 74, moreover, the body 78 of the flow
regulating cloth 77 is arranged to cover the gas inlet port 23 and
the body 8a of the inflator 8. Therefore, the flow regulating cloth
body 78 can protect the area of the passenger-facing wall portion
25 directly opposite the gas inlet port 23, against the inflating
gas G.
[0223] Here, the first and second embodiments of the airbag
invention M1 and M2 for the steering wheel. As shown in FIGS. 15 to
18, however, the invention may also be applied to an airbag device
M3 for a passenger's seat according to a third embodiment. This
airbag device M3 is arranged in an instrument panel (hereafter
abbreviated "panel") in front of the passenger's seat.
[0224] This airbag device M3 is provided, as shown in FIG. 17A,
with a folded airbag 100, an inflator 94 for feeding the airbag 100
with the inflating gas, a cover member 98 for covering the folded
airbag 100, and a case 92. This case 92 houses the folded airbag
100 and the inflator 94 and holds the cover member 98.
[0225] The case 92 is formed of a sheet metal into a generally
rectangular shape and is provided with a bag housing portion 92a on
its upper side and an inflator housing portion 92c on its lower
side. The bag housing portion 92a houses the folded airbag 100. The
inflator housing portion 92c houses the inflator 94. A step portion
92b is formed in the bottom portion of the bag housing portion 92a.
Moreover, the airbag 100 is mounted and fixed on the step portion
92b by having the periphery of the later-described gas inlet port
102a of the airbag held down by a retainer 96. In the inflator
housing portion 92c, there is formed a mounting portion 92d to
which nuts are fixed for mounting this housing on the vehicle
body.
[0226] The cover member 98 is made of a synthetic resin and is so
arranged and fixed on the case 92 as to close the opening 90a of
the panel 90. The cover member 98 is provided with two door
portions 98a, which are opened forward and rearward respectively
when the airbag 100 is inflated.
[0227] The airbag 100 is provided with an airbag body 101 and a
flow regulating cloth 113 acting as the flow regulating member.
Both the airbag body 101 and the flow regulating cloth 113 are
formed of a woven fabric having flexibility such as polyamide or
polyester.
[0228] The airbag body 101 comprises, as shown in FIG. 15, a
vehicle front-facing wall portion 102, an upper wall portion 103, a
lower wall portion 104, a passenger-facing wall portion 107, and
right and left side wall portions 105 and 106. The vehicle
front-facing wall portion 102 is provided with the gas inlet port
102a, which is opened generally in a rectangular shape for the
inflating gas to flow in. The upper wall portion 103 extends from
the upper edge of the vehicle front-facing wall portion 102 toward
the passenger. The lower wall portion 104 extends from the lower
edge of the vehicle front-facing wall portion 102 toward the
passenger. The passenger-facing wall portion 107 is connected to
the passenger facing ends of the upper wall portion 103 and the
lower wall portion 104 and is arranged to be directly opposite the
gas inlet port 102a. In the periphery of the gas inlet port 102a of
the vehicle front-facing wall portion 102, there are formed
mounting holes 102b through which are passed a plurality of bolts
96a (as referred to FIG. 17) extending from the retainer 96.
Moreover, the airbag body 101 of the third embodiment comprises
four base cloths of three shapes 109, 110, 110 and 111, that is:
the first base cloth 109 forming the upper wall portion 103, the
vehicle front-facing wall portion 102 and the lower wall portion
104; the two second base cloths 110 forming the right and left side
wall portions 105 and 106 individually; and the third base cloth
111 forming the passenger-facing wall portion 107.
[0229] The flow regulating cloth 113 as the flow regulating member
is provided with a rectangular opening 113a for communicating with
the gas inlet port 102a. On the periphery of the opening 113a in
the flow regulating cloth 113, there are arranged flow regulating
band members 114 and 114 extending along the right and left sides
of the flow regulating cloth. Moreover, the flow regulating bands
114 are superposed at their two end portions 114a and this
superposed area is sewn to the passenger-facing wall portion 107 by
means of the sewing thread 53. In other words, the leading end
portions 114a of the flow regulating band members 114 are sewn to
form a passenger side joint portion 115 to be jointed to the
passenger-facing wall portion 107. In the periphery of the opening
113a, there are formed a plurality of mounting holes 113b through
which are passed the individual bolts 96a of the retainer 96.
Moreover, the periphery of the opening 113a serves as the vehicle
front-facing joint portion 118, which is held down by the retainer
96 and jointed to the vehicle front-facing wall portion 102. In
each band member 114, moreover, easily torn portions 116 are formed
by arraying a plurality of slits.
[0230] This flow regulating cloth 113 is sewn in advance to the
third base cloth 111 at the superposing end portions 114a of the
band members 114 and 114. Then, the edges of the individual base
cloths 109, 110 and 111 are sewn to one another to manufacture the
airbag 100. Next, the retainer 96 is arranged in the airbag 100,
and the individual bolts 96a are passed through the mounting holes
113b of the flow regulating cloth 113 and the mounting holes 102b
of the vehicle front-facing wall portion 102. In this state,
moreover, the airbag 100 is folded and is housed in the bag housing
portion 92a of the case 92 having the inflator 94 housed therein.
At this time, the individual bolts 96a of the retainer 96 are
protruded from the step portion 92b of the case 92, and nuts are
fastened on the individual bolts 96a. As a result, the vehicle
front-facing joint portion 118 of the flow regulating cloth 113 can
be jointed to the vehicle front-facing wall portion 102 of the
airbag body 101, and the airbag 100 can be held in the case 92.
[0231] The inflator 94 and the airbag 100 are housed in the case
92, and the cover member 98 is mounted on the case 92. After this,
the case 92 is mounted and fixed on the vehicle so that the airbag
device M3 can be mounted on the vehicle. If the inflator 94 is
activated, moreover, the folded airbag 100 is so inflated as to
push and open the door portions 98a and 98a of the cover member 98
and to protrude from the opening 90a of the panel 90, as shown in
FIGS. 17A and 17B.
[0232] At this time, the inflating gas G is regulated in its flow
toward the front and rear of the vehicle by the right and left flow
regulating band members 114 and 114 of the flow regulating cloth
113 between the vehicle front-facing joint portion 118 and the
passenger side joint portion 115. Thereafter, the airbag 100 is
inflated along the outer surface of the panel 90 to the front and
rear of the vehicle. At this time, it is natural that the
individual flow regulating band members 114 of the flow regulating
cloth 113 serve to regulate the spacing distance of the
passenger-facing wall portion 107 from the gas inlet port 102a
through their the vehicle front-facing joint portions 118 and the
passenger side joint portion 115. Therefore, the airbag 100 can be
prevented from unnecessarily protruding to the passenger (or the
passenger on the front passenger seat).
[0233] If the individual flow regulating band members 114 are torn
at easily torn portions 116, moreover, the airbag 100 can complete
its inflation while allowing the inflating gas G to freely flow in
from the gas inlet port 102a without being regulated, as shown in
FIG. 18.
[0234] Here in this airbag device M3 for the front passenger's
seat, the passenger side joint portion 115 of the flow regulating
cloth 113 is arranged to close the gas inlet port 102a of the
airbag body 101. As in the flow regulating cloth body 37 of the
airbag device M1 of the first embodiment, however, the flow
regulating cloth near the opening 113a may be enlarged and made to
serve as the passenger-facing wall portion 107 so that the
passenger side joint portion 115 does not close the gas inlet port
102a. Here, as with the airbag device M1, the gas outlet ports are
arranged between the vehicle front-facing joint portion 118 and the
passenger side joint portion 115.
[0235] In the airbag 100 of the third embodiment, moreover, the end
portions 114a of the individual flow regulating band members 114 of
the flow regulating cloth 113 are jointed to the passenger-facing
wall portion 107. However, the end portions 114a need not be
jointed to the passenger-facing wall portion 107 but may be sewn to
each other. In this modification, the passenger side joint portion
115 is not provided, but the flow of the inflating gas G from the
gas inlet port 102a can be regulated by the flow regulating band
members 114 and 114 which are arranged to close the gas inlet port
102a. If the easily torn portions 116 are torn before the
completion of inflation, moreover, it is possible to promote the
completion of inflation of the airbag.
[0236] Here will be described an airbag device M4 capable of
achieving the third object of the invention.
[0237] The airbag device M4 of the fourth embodiment is provided
for the steering wheel like the foregoing airbag devices M1 and M2,
and has a construction similar to that of the aforementioned airbag
device M1 excepting the airbag 220. Therefore, common members are
given the same reference numerals.
[0238] The airbag 220 is provided with an airbag body 221 and an
auxiliary inflation portion 236 to be arranged in the airbag body
221, as shown in FIGS. 19 and 20. Here, the airbag body 221 has a
construction similar to that of the airbag body 21 of the airbag 20
in the foregoing airbag device M1. Therefore, the description will
be omitted by designating the common members by the common
reference numerals.
[0239] The auxiliary inflation portion 236 is formed of an
inflation portion cloth member 237 made of a woven fabric having
flexibility such as polyamide or polyester, as in the airbag body
221. This inflation portion cloth member 237 is provided, as shown
in FIG. 19, with a generally disc-shaped flat plate portion 237a,
and band-shaped portions 237b and 237b extending in a band shape
from the flat plate portion 237a to the right and left. The
individual band-shaped portions serve as tethers 243.
[0240] Toward the center of the flat plate portion 237a, moreover,
there is arranged a vehicle front-facing joint portion 238 to be
joined to the vehicle front-facing wall portion 22 in the airbag
body 221. At the center of the vehicle front-facing joint portion
238, there is formed an opening 238a for communicating with the gas
inlet port 23 of the airbag body 221. In the periphery of the
opening 238a, moreover, there are formed four mounting holes 238b
through which will be passed the individual bolts 6a of the
retainer 6. The body 8a of the inflator 8 is inserted upward into
the opening 238a like the opening 37a of the airbag 20 in the
aforementioned airbag device M1. Moreover, the whole periphery of
the opening 238a is joined by being held down by the retainer 6 to
the vehicle front-facing wall portion 22 and thus becomes the
vehicle front-facing joint portion 238.
[0241] Toward the outer circumference of the flat plate portion
237a, there is arranged a passenger side joint portion 242 to be
sewn and jointed to the passenger-facing wall portion 25 by means
of the sewing thread 53. A sewing location 250 at which to the
passenger side joint portion 242 is in an annular shape around the
gas inlet port 23. Moreover, the sewing location 250 is arranged to
surround the portion 25a of the passenger-facing wall portion 25
directly opposite the gas inlet port 23. This passenger side joint
portion 242 is formed toward the outer circumference of the flat
plate portion 237a of the single inflation portion cloth member
237. Specifically, the passenger side joint portion 242 is arranged
around both the gas inlet port 23 and the vehicle front-facing
joint portion 238 formed near the center of the flat plate portion
237a. Here in the case of the fourth embodiment, the sewing
location 250 is sized to have an external diameter of 300 mm, and
the passenger-facing wall portion 25 is sized to have an external
diameter of 680 mm when expanded flat.
[0242] Between the vehicle front-facing joint portion 238 in the
flat plate portion 237a and the passenger side joint portion 242,
moreover, there is formed a cylindrical wall portion 239 which
forms the circumferential wall when the auxiliary inflation portion
236 is inflated. Here in the auxiliary inflation portion 236 at the
time of inflation completion, as shown in FIG. 20, the
circumferential wall portion 239 rises to form a downward tapering
tubular shape joined at the bottom to the annular-shaped vehicle
front-facing joint portion 238 on the periphery of the gas inlet
port 23. On the other hand, the passenger side ceiling wall portion
244 of the auxiliary inflation portion 236 is formed of the portion
25a of the passenger-facing wall portion 25 directly opposite the
gas inlet. Moreover, the tapering tubular circumferential wall
portion 239 forms the partition with the airbag body 221.
[0243] In this circumferential wall portion 239, there are formed
gas outlet ports 240 and the easily torn portions 41. The gas
outlet ports 240 and the easily torn portions 41 have constructions
similar to those of the gas outlet ports 40 and the easily torn
portions 41, as arranged in the airbag 20 of the aforementioned
airbag device M1, and their description will be omitted. Here, the
areas of openings of the gas outlet ports 240 and 240 in the airbag
220 of the fourth embodiment are set at such a size as can reserve
the inflow of the inflating gas once and can retain the internal
pressure for the cushioning action even at a low temperature. When
the portions 41 are ruptured, moreover, the portions between the
vehicle front-facing joint portion 238 and the passenger side joint
portion 242 are broken to end the inflated state of the auxiliary
inflation portion 236.
[0244] The tethers 243 and 243 are formed from the right and left
side band-shaped portions 237b of the inflation portion cloth
member 237, as has been described. Moreover, the individual tethers
243 are joined by sewing their end portions 243a to the end
portions 31d of the extension portions 31c in the reinforcing cloth
31 on the side of the vehicle front-facing wall portion 22 by means
of the sewing thread 53, thereby being brought closer to the gas
inlet port 23. Moreover, the tethers 243 and 243 regulate the
spacing distance of the portion 25a of the passenger-facing wall
portion 25 directly opposite the gas inlet port 23 from the gas
inlet port 23 by regulating the shape of the airbag body 221 when
inflation is completed. Here, the spacing distance from the gas
inlet port 23 to the directly opposite portion 25a by the tethers
243 is set longer than that at the time of regulation of the
circumferential wall portion 238.
[0245] The airbag 220 of the fourth embodiment can be manufactured
like the airbag 20 in the airbag device M1 of the first embodiment.
Moreover, the airbag 220 can be folded and mounted on the vehicle
like the airbag 20 in the airbag device M1.
[0246] At the beginning of the operation of the airbag device M4,
moreover, the inflating gas G discharged from the gas discharge
ports 8b of the inflator body 8a fills first the auxiliary
inflation portion 236 surrounded by the vehicle front-facing joint
portion 238, the circumferential wall portion 239 and the ceiling
wall portion 244, as shown in FIG. 20, to inflate the auxiliary
inflation portion 236. Simultaneously with this, the inflating gas
G flows from the gas outlet ports 240 and 240 into the airbag body
221 in the forward and rearward directions.
[0247] When the inflating gas G flows into the airbag body 221 so
that the internal pressure of the airbag body 221 reaches a
predetermined level, moreover, a predetermined or higher tension is
built up between the passenger side joint portion 242 and the
vehicle front-facing joint portion 238 within the cylindrical wall
portion 239 so that the easily torn portions 41 and 41 are torn to
disconnect the passenger-facing wall portion 25 and the vicinity of
the gas inlet port 23. There after, the inflating gas G from the
gas discharge port 8b in the body 8a of the inflator 8 flows
radially from the gas inlet port 23 without being directionally
regulated, so that the airbag body 221 completes its inflation. At
this time, the airbag body 221 completes the inflation with the
interval between the portion 25a of the passenger-facing wall
portion 25 directly opposite the gas inlet port and the gas inlet
port 23 regulated by the tethers 243 and 243.
[0248] In the fourth embodiment, as described above, at the
beginning of expansion of the airbag 220, the auxiliary inflation
portion 236 completes its inflation while causing the inflating gas
G to flow out from the gas outlet ports 240 and 240 to the airbag
body 221, as shown in FIG. 20. Although the entering inflating gas
G has a smaller volume at a low temperature at this time, the gas
outlet ports 240 and 240 are not excessively wide, so that the
amount of flow of the inflating gas G out into the airbag body 221
is small. Therefore, the auxiliary inflation portion 236 can raise
the internal pressure and can inflate to retain the cushioning
action thereby to protect the passenger (or the driver).
[0249] After this, the auxiliary inflation portion 236 ends its
inflated state by breaking at the portions 41 and 41 which are
removed from both the vehicle front-facing wall portion 22 and the
passenger-facing wall portion 25 comprising the outer wall of the
airbag body 221. From this partially inflated state in which the
inflating gas G from the gas outlet port 23 has already been
admitted, the airbag body 221 completes the inflation, by further
admitting the inflating gas G smoothly and promptly. At the time of
this end of regulation of inflation, the auxiliary inflation
portion 236 is broken at the easily torn portions 41 removed from
the outer wall of the airbag body 221. Therefore, the airbag body
221 can complete its inflation without affecting the sewing
location 250, although the passenger side joint portion 242 of the
auxiliary inflation portion 236 is joined by sewing to the
passenger-facing wall portion 25 of the airbag body 221.
[0250] In other words, the airbag 220 can be conveniently
manufactured without the need to apply a seal material to the joint
portions 238 and 242 joining the auxiliary inflation portion 236
and the airbag body 221.
[0251] In the airbag device M4 of the fourth embodiment in which
the auxiliary inflation portion 236 capable of protecting the
passenger (or the driver) at a low temperature is arranged in the
airbag 220, therefore, the unnecessary gas leakage from the airbag
220 can be prevented in such a way that the airbag 220 can be
manufactured with a reduced number of steps and at a lower
cost.
[0252] In the fourth embodiment, moreover, the auxiliary inflation
portion 236 causes the inflating gas G, when inflated, to flow out
forward and rearward from the gas outlet ports 240 and 240 opened
in the front and rear of the circumferential wall portion 239 to
the airbag body 221. Therefore, the auxiliary inflation portion 236
plays the role of the flow regulating member for controlling the
flow of the inflating gas G. By this flow of the inflating gas G,
the airbag body 221 can be expanded widely in these two
longitudinal directions while being prevented from protruding to
the passenger (or to the driver). Even if the passenger is close to
the airbag device M4 at the beginning of inflation so that there is
narrow spacing between the passenger and the airbag device M4,
therefore, the airbag body 221 can be easily expanded and arranged
between the passenger and the airbag device M4. By the subsequent
inflation of the airbag body 221, the cushioning effect can be
enhanced to protect the passenger over the wide area of the airbag
body 221.
[0253] In the fourth embodiment, therefore, the auxiliary inflation
portion 236 of the airbag 220 can be used as the flow regulating
member. In other words, it is possible to manufacture the airbag
220 without increase in the number of components of the airbag 220
while preventing the airbag body 221 from protruding to the
passenger at the beginning of inflation.
[0254] Especially in the case of the fourth embodiment, the airbag
220 is constructed for the steering wheel. Moreover, the inflating
gas G flowing from the auxiliary inflation portion 236 serving as
the flow regulating member flows forward and rearward perpendicular
to the axis of the steering shaft SS and forward and backward over
the ring portion R of the steering wheel W. Therefore, the airbag
body 221 has its rearward portion extended from the beginning of
inflation over the rear portion Rb of the ring portion R of the
steering wheel W, like the airbag 20 in the aforementioned airbag
device M1. As a result, the airbag 220 of the fourth embodiment can
attain effects similar to those of the airbag 20 in the airbag
device M1 of the first embodiment.
[0255] In the fourth embodiment, on the other hand, the outer wall
portion 239 joins the passenger side joint portion 242 and the
vehicle front-facing joint portion 238 at the upper and lower ends
to the passenger-facing wall portion 25 and the vehicle
front-facing wall portion 22 before the completion of inflation of
the airbag body 221, i.e., before the auxiliary inflation portion
236 is deflated. Therefore, the distance between the periphery of
the gas inlet port 23 of the vehicle front-facing wall portion 22
and the portion 25a of the passenger-facing wall portion 25
directly opposite the gas inlet port can be kept within a small
value in the airbag body 221. As a result, the airbag body 221 can
prevent the passenger-facing wall portion 25 from unnecessarily
protruding to the passenger from the beginning to a point midway in
inflation regardless of the flow direction of the inflating gas
G.
[0256] If the above points are not of concern, the auxiliary
inflation portion 236 need not be joined to the passenger-facing
wall portion 25. In this case, the the auxiliary inflation portion
236 may be deflated by tearing the periphery of the gas outlet
ports 240, 240 as the internal pressure of the auxiliary inflation
portion rises.
[0257] In the fourth embodiment, on the other hand, a plurality of
(two in the embodiment) gas outlet ports 240 are aligned radially
along the circumferential wall portion 239. Moreover, the easily
torn portions 41 of the auxiliary inflation portion 236 in the form
of slits are preformed between the gas outlet ports 240 and 240.
Therefore, the auxiliary inflation portion 236 is properly broken
at the easily torn portions 41. Moreover, the easily torn portions
41 connect the gas outlet ports 240 and 240 when torn so that the
circumferential wall portion 239 of the auxiliary inflation portion
236 can be vertically separated efficiently and quickly. As a
result, the airbag body 221 can complete its inflation promptly by
admitting the inflating gas G smoothly and quickly.
[0258] The gas outlet ports 240 and 240 of the auxiliary inflation
portion 236 are arranged in plurality so that the flow of the
inflating gas G to be fed from the gas outlet ports 240 and 240 to
the airbag body 221 can be set in the two longitudinal directions
outward from the gas inlet port 23 and away from each other. It is
quite natural that the airbag body 221 at the beginning of
inflation can be more widely expanded.
[0259] Here in the fourth embodiment, the gas outlet ports 240 and
240 are arranged in the front of and at the rear of the
circumferential wall portion 239. The same effects may be achieved
by arranging the gas outlet ports 240 and 240 to the right and left
of the circumferential wall portion 239 or by arranging three or
more gas outlet ports aligned in the circumferential direction of
the circumferential wall portion 239.
[0260] On the other hand, the portions 41 are broken through the
tension applied to the circumferential wall portion 239. By using
the heat of the inflating gas G, however, the material between the
slits in the easily torn portions 41 may be partially molten to
break the circumferential wall portion 239.
[0261] In the fourth embodiment, moreover, in the auxiliary
inflation portion 236 of the airbag 220 the cylindrical
circumferential wall portion 239 extending from the vehicle
front-facing wall portion 22 at the periphery of the gas inlet port
23 of is joined to the passenger-facing wall portion 25 of the
airbag body 221. Moreover, the portion 25a of the passenger-facing
wall portion 25 in the airbag body 221 directly opposite the gas
inlet port is used as the ceiling wall portion 244 of the auxiliary
inflation portion 236 on the passenger side. Therefore, in the
auxiliary inflation portion 236 of the fourth embodiment a member
at the passenger-facing side of the circumferential wall of the
auxiliary inflation portion 236 can be omitted, in contrast with
the case in which there is separately provided a member for
covering the portion of the circumferential wall portion 239 on the
passenger side.
[0262] If the above points are not of concern, the ceiling wall
portion 244 of the auxiliary inflation portion 236 maybe formed
separately from the passenger-facing wall portion 25. In this case,
the ceiling wall portion 244 and the passenger-facing wall portion
25 have to be separately connected by means of a connection member
so that the easily torn portions 41 of the circumferential wall
portion 239 may be ruptured, before the completion of inflation of
the airbag body 221. Moreover, the expanded shape of the auxiliary
inflation portion 236 may be formed into a sphere, the topmost area
of which is joined directly to the passenger-facing wall portion 25
by sewing means or the like. In this case, too, the easily torn
portions 41 are formed at portions apart from the passenger-facing
wall portion 25, e.g., in one circumferential line around the gas
inlet port 23 in the outer wall of the auxiliary inflation portion
236. In this way it is possible to prevent the gas leakage from the
portion jointed to the passenger-facing wall portion 25.
[0263] In the auxiliary inflation portion 236 of the fourth
embodiment, moreover, the circumferential wall portion 239 is
formed so that its passenger side joint annular portion 244 is
further from the axis of the gas inlet port 23 than the vehicle
front-facing joint portion 238. Therefore, the auxiliary inflation
portion 236 is a frustrum converging downward, wider on the side of
the ceiling wall portion 244 (or on the passenger side) than on the
side of the gas inlet port 23. Moreover, the ceiling wall portion
244 is the passenger-facing wall portion 25 of the airbag body 221
itself. Therefore, the auxiliary inflation portion 236 can protect
the passenger interfering with the inflation of the airbag at the
beginning ostage, directly in a wide area with enhanced cushioning
effect.
[0264] With the auxiliary inflation portion 236 being bulged into a
frustrum converging downward, on the other hand, the gas outlet
ports 240 and 240 formed in the circumferential wall portion 239
discharge the inflating gas G to the airbag body 221 while being
directed slightly downward toward the vehicle front-facing wall
portion 22. Therefore, the airbag body 221 can be inflated while at
the same time suppressing the protrusion toward the passenger.
[0265] In the fourth embodiment, moreover, there are arranged in
the airbag 220 the tethers 243 and 243 for connecting the vehicle
front-facing wall portion 22 and the passenger-facing wall portion
25. Like the aforementioned airbag device M1, therefore, the airbag
body 221 can be prevented from unnecessarily protruding toward the
passenger at the completion of inflation.
[0266] In the fourth embodiment, moreover, the tethers 243 and 243
are formed into integral units extended from the circumferential
wall portion 239 of the auxiliary inflation portion 236. In other
words, the tethers 243 need not to be separately attached to the
airbag 220. Like the airbag 20 in the aforementioned airbag device
M1, therefore, the airbag 220 having the tethers 243 and 243 can be
manufactured with a reduced number of steps and at a lower
cost.
[0267] In the fourth embodiment, on the other hand, the vehicle
front-facing joint portion 238 and the leading ends of the tethers
243 and 243 are formed of the single inflation portion cloth member
237. By using only one inflation portion cloth member 237,
therefore, it is possible to conveniently manufacture the airbag
220 which includes an auxiliary inflation portion 236 and which can
regulate the shape of the airbag body 221 at the two stages, i.e.,
from the beginning to a point midway in inflation and from that
point to the completion of inflation.
[0268] In the fourth embodiment, still moreover, the vehicle
front-facing joint portion 238 is held down by the retainer 6 and
so is joined to the vehicle front-facing wall portion 22. Like the
airbag 20 in the aforementioned airbag device M1, therefore, it is
possible to form the vehicle front-facing joint portion 238 of the
circumferential wall portion 239 easily.
[0269] Here in the fourth embodiment, the capacity of the auxiliary
inflation portion 236 of the airbag 220 can be altered by adjusting
the length between the vehicle front-facing joint portion 238 and
the passenger side joint portion 242. For a larger capacity, for
example, the passenger side joint portion 242 may be brought closer
to the outer circumferential edge of the disc-shaped flat plate
portion 237a. At this time, the protrusion to the passenger can
also be increased as the capacity of the auxiliary inflation
portion 236 increases. If the entire disc portion of the flat plate
portion 237a is enlarged as well as bringing the passenger side
joint portion 242 closer to its outer circumferential edge,
moreover, it is possible to enlarge the capacity of the auxiliary
inflation portion 236 and the protrusion to the passenger all the
more. When the capacity of the auxiliary inflation portion 236 and
the protrusion to the passenger are to be reduced, on the contrary,
the external diameter of the passenger side joint portion 242 may
be reduced.
[0270] Here, the fourth embodiment has been described on the airbag
device M4 for the steering wheel, but the invention may also be
applied to an airbag device for a passenger's seat.
[0271] Next will be described an airbag device M5 capable achieving
the fourth object of the invention.
[0272] Like the aforementioned airbag devices M1, M2 and M4, the
airbag device M5 of the fifth embodiment is provided for the
steering wheel and has a construction similar to that of the
aforementioned airbag device M1 excepting an airbag 361. Therefore,
common members are given the same reference numerals.
[0273] The airbag 361 is provided with an airbag body 362, a flow
regulating cloth material 372 and a second flow regulating cloth
345. Here, the airbag body 362 has a construction similar to that
of the airbag body 21 in the aforementioned airbag device M1.
Therefore, common members are given the same reference
numerals.
[0274] The flow regulating cloth material 372 is made, like the
airbag body 362, of a woven fabric having flexibility such as
polyamide or polyester. The flow regulating cloth material 372 is
provided with a first flow regulating cloth 364 and two second
regulating members 371 and 371. Moreover, a flow regulating cloth
material 372 is formed into a band shape having uniform width. In
the first flow regulating cloth 364, at the center of the flow
regulating cloth material 372 and at two portions of the flow
regulating cloth material 372 longitudinally spaced from the
center, there are arranged passenger side joint portions 366 where
the passenger side base cloth 29 of the passenger-facing wall
portion 25 is sewn. These two passenger side joint portions 366
(366L and 366R) are arranged on either side of a later-described
opening 364a. Moreover, the individual passenger side joint
portions 366 are both linear at a right angle to the flow
regulating cloth material 372.
[0275] On the other hand, the portions to the inside of the
passenger side joint portions 366L and 366R in the first flow
regulating portion 364 comprise the body 365 of the flow regulating
cloth 364 which is the first regulating member 365. In the center
of the body 365, there are formed the opening 364a and four
mounting holes 364b around the opening 364a. This opening 364a is
formed into a circular shape similar to the gas inlet port 23
through which the inflator body 8a can pass. Moreover, the entire
periphery of the opening 364a comprises the vehicle front-facing
joint portion 368 which is held down by the retainer 6 and so
joined to the vehicle front-facing wall portion 22. Between the
vehicle front-facing joint portion 368 and the individual passenger
side joint portions 366L and 366R, on the other hand, there are
arranged easily torn portions 369 and 369. These individual easily
torn portions 369 are formed linearly by slits or perforations.
Moreover, the individual easily torn portions 369 are arranged
parallel to the passenger side joint portions 366. These easily
torn portions 369 are torn when the internal pressure of the airbag
body 362 reaches a predetermined level (10 to 20 KPa). When the
portions 369 are torn, moreover, the passenger side joint portions
366 and the vehicle front-facing joint portion 368 in the body 365
are disconnected. Before the breakage of the individual portions
369 of the body 365, this body 365 regulates the distance from the
gas inlet port 23 to the portion 25a of the passenger-facing wall
portion 25 directly opposite the gas inlet port 23. Therefore, the
body 365 constructs the first regulating member 365.
[0276] The second regulating members 371 of the flow regulating
cloth material 372 extend from the sewing location 53 to edge
portions 371a. These second regulating members 371 and 371 are made
longer in the longitudinal direction of the cloth material 372 than
the first regulating member 365. Moreover, the individual second
regulating members 371 are sewn at their edge portions 371a to the
edge portions 31d of the edge portions 31d of the reinforcing cloth
31c, as shown in FIG. 22.
[0277] The second flow regulating cloth 345 is formed of a
rectangular woven fabric having a flexibility such as polyamide or
polyester. The second flow regulating cloth 345 is provided at its
two right and left longitudinal ends with joint portions 345b to be
jointed to the vehicle front-facing wall portion 22. In the joint
portions 345b, there are formed (not-shown) mounting holes through
which are passed the bolts of the retainer 6. Moreover, the is
joined to the periphery of the gas inlet port 23 of the vehicle
front-facing wall portion 22 by folding down the joint portions
345b at the right and left sides of the second flow regulating
cloth 345 and by arranging the retainer 6 on the upper faces of the
folded sides, as shown in FIG. 22. At this time, the joint portions
345b are joined to the vehicle front-facing wall portion 22 with
the periphery of the opening 364a of the first flow regulating
cloth 364 interposed.
[0278] Moreover, the body 345a between the right and left joint
portions 345b and 345b of the second flow regulating cloth 345
covers over the gas inlet port 23 and the opening 364a. The body
portion 345a is in a band shape with the two right and left ends
joined to the vehicle front-facing wall portion 22. Therefore, the
body 345a causes the inflating gas from the inflator 8 to flow to
the two longitudinal sides.
[0279] The airbag 361 of the fifth embodiment can be manufactured
like the airbag 20 in the airbag device M1 of the first embodiment.
Moreover, the airbag 361 can be folded and mounted on the vehicle
like the airbag 20 in the airbag device M1.
[0280] When the inflating gas is discharged from the gas discharge
ports 8b of the inflator body 8a, moreover, the airbag device M5 of
the fifth embodiment acts in the following manner from the
beginning to a point midway in inflation of the airbag 361.
[0281] First of all, a portion 365a located between the left of the
vehicle front-facing joint portion 368 and the passenger side joint
portion 366L in the body 365 of the first flow regulating cloth 364
and a portion 365b located between the right of the vehicle
front-facing joint portion 368 and the passenger side joint portion
366R in the body 365 extend in the vertical direction. Moreover,
the first regulating member 365 is such constructed by these
portions 365a and 365a to regulate the spacing distance D1 from the
gas inlet port 23 to the portion 25a of the passenger-facing wall
portion 25 directly opposite the gas inlet port, as shown in FIG.
23A. Therefore, an unnecessary protrusion to the passenger (or the
driver) can be suppressed. On the other hand, the inflating gas G
is so guided by the portions 365a and 365b of the body 365 to flow
into the airbag body 362 in the width directions of the flow
regulating material 372 toward the two longitudinal ends of the
vehicle. Therefore, the two longitudinal sides of the airbag body
362 are expanded widely while the airbag is prevented from
protruding to the driver.
[0282] When the internal pressure of the airbag body 362 reaches a
predetermined level, moreover, the portions 369 and 369 are torn so
that the passenger-facing wall portion 25 and vehicle front-facing
wall portion 22 in the vicinity of the gas inlet port 23 are
disconnected. Further, the body 345a of the second flow regulating
cloth 345 is expanded.
[0283] After this, the inflating gas G flowing into the airbag body
362 is so regulated by the body 345a of the second flow regulating
cloth 345 as to flow into the airbag body 362 toward the airbag's
two longitudinal sides. Then, the airbag 361 completes its
inflation while elongating the second regulating members 371 and
371, as shown in FIG. 23B. At this time, the airbag 361 completes
its inflation such that the spacing distance from the gas inlet
port 23 to the portion 25a of the passenger-facing wall portion 25
directly opposite the gas inlet port is limited to D2 by the second
regulating members 371 and 371. In short, the airbag 361 completes
its inflation by expanding its width as much as possible while
suppressing the protrusion to the driver. Even if the driver
interferes with the passenger-facing wall portion 25 just before
the completion of inflation of the airbag 361, therefore, the
interference with the driver is made with the passenger-facing wall
portion 25 being widely expanded, so that the airbag 361 can
protect the driver without any of its pushing force applied to the
passenger.
[0284] Therefore, the airbag device M5 of the fifth embodiment can
protect the passenger properly with the airbag 361 while
suppressing unnecessary protrusion to the passenger from the
beginning to a point midway in inflation.
[0285] In the fifth embodiment as well, the two flow regulating
cloths 364 and 345 of the airbag 361 regulate the inflating gas G
to the two longitudinal sides perpendicular to the axis of the
steering shaft. As a result, the flow regulating cloths 364 and 345
regulate, when mounted on the vehicle, the flow of the inflating
gas G in the two longitudinal directions of the vehicle along the
plane of the ring portion of the steering wheel. Therefore, the
airbag 361 is inflated, like the airbag 20 in the foregoing first
embodiment, to extend to the two longitudinal directions of the
plane of the ring portion. Moreover, the airbag 361 of the fifth
embodiment can also perform actions similar to those of the airbag
20 in the foregoing first embodiment.
[0286] In the airbag 361 of the fifth embodiment, on the other
hand, the regulation of the spacing distance D1 in the first
regulating member 365 is released by tearing the easily torn
portions 369 of the first regulating member 365. Like the airbag 20
of the foregoing first embodiment, therefore, there is no needless
gas leakage from the airbag 361 which has completed its
inflation.
[0287] In the fifth embodiment, the flow regulating cloth of the
airbag 361 is provided with the first flow regulating cloth 364 for
regulating the flow of the inflating gas G from the beginning to a
point midway in inflation, and the second flow regulating cloth 345
for regulating the flow of the inflating gas G until the completion
of inflation. Moreover, the first flow regulating cloth 364 is the
first regulating member 365.
[0288] For the flow regulation of the inflating gas G, therefore,
it is possible to use the first flow regulating cloth 364 from the
beginning to a point midway in inflation of the airbag 361 and to
use the second flow regulating cloth 345 till the subsequent
completion of inflation of the airbag 361. In this airbag device
M5, more specifically, the flow rate of the inflating gas G can be
adjusted to correspond to the depth of the airbag 361 (i.e., the
spacing distances D1 and D2 from the gas inlet port 23 to the
portion 25a of the passenger-facing wall portion 25 directly
opposite to the gas inlet port). It is also possible to properly
retain the width of the expanded airbag 361 according to the time
elapsed since start of inflation. This is because, when the flow of
the inflating gas G in the airbag device M5 is being regulated by
the body 365 of the first flow regulating cloth 364, the inflating
gas G can be accelerated to flow to the two longitudinal sides of
the airbag to expand them quickly. This is also because, flow flow
is being regulated by the second flow regulating cloth 345, the
completion of inflation of the airbag body 362 as a whole can be
promoted by increasing the rate of feeding the inflating gas G to
the two longitudinal sides.
[0289] In the fifth embodiment, moreover, the first flow regulating
cloth 364 plays the role of the first regulating member 365. Thus,
even if the flow regulating cloth comprises a first flow regulating
cloth 364 and a second flow regulating cloth 345, therefore, it is
still possible to minimize the increase in the number of components
of the airbag 361.
[0290] Here in the fifth embodiment, the second flow regulating
cloth 345 is constructed to guide the flow of the inflating gas to
the two longitudinal sides. If desired, of course, the second flow
regulating cloth 345 may naturally be constructed to feed the
inflating gas G in a direction different from the flow direction of
the first flow regulating cloth 364, such as to the two transverse
sides or backward. In this modification, at the beginning of
inflation of the airbag, the second flow regulating cloth may be
holed or have arch portions for passing the inflating gas while
keeping its flow regulating function, so that it may not obstruct
the flow regulated by the first flow regulating cloth.
[0291] In the fifth embodiment, moreover, the single flow
regulating cloth material 372 comprises the first flow regulating
cloth 364 and the second flow regulating member 371. As compared
with the case in which the first and second regulating members are
separately arranged, therefore, it is possible to make the number
of components smaller. Moreover, the joints of the first and second
regulating members 365 and 371 to the passenger-facing wall portion
25 are both provided by the joint portions 366. Therefore, it is
possible to simplify the joining of the first and second regulating
members 365 and 371 to the passenger-facing wall portion 25. Even
if the flow regulating cloth comprises first and second flow
regulating cloths 364 and 345, therefore, it is possible to
minimize the increase in the number of steps of and the rise in the
cost for manufacturing the airbag 361.
[0292] Here in the fifth embodiment, the edge portions 31c of the
reinforcing cloth 31 sewn to the vehicle front-facing wall portion
22, are sewn to the edge portions 371a of the second regulating
members 371 extended toward the vehicle front-facing wall portion
22, so that the second regulating members 371 are jointed to the
side of the vehicle front-facing wall portion 22. Like the use of
tethers 45 in the airbag 20 of the afore mentioned first
embodiment, therefore, it is easy to join the second regulating
member 371 to the vehicle front-facing wall portion 22.
[0293] If the above points are not of concern, a plurality of
second regulating members may be made separately from the first
regulating member 365 and the reinforcing cloth 31, and the lower
and upper edges joined respectively to the vehicle front-facing
wall portion 22 and the passenger-facing wall portion 25. In this
case, further, the edges of the second regulating members maybe
integrated at the vehicle front-facing wall portion 22 and the
passenger-facing wall portion 25 for joint use.
[0294] In the fifth embodiment, on the other hand, the flow
regulating cloth 364 is held to the vehicle front-facing wall
portion 22 by the retainer 6 to form joint portion 368. Like the
airbag 20 of the foregoing first embodiment, therefore, it is
possible to form the vehicle front-facing joint portion 368 of the
first flow regulating cloth 364 easily. In the case of the fifth
embodiment, on the other hand, the second flow regulating cloth 345
is also jointed to the vehicle front-facing wall portion 22 by the
retainer 6. Therefore, the second flow regulating cloth 345 can be
easily arranged in the airbag 361.
[0295] Here in the fifth embodiment, it is also feasible to arrange
a flow regulating cloth 363 (as referred to double-dotted lines in
FIGS. 23A and 23B) which is shorter to the right and left of the
passenger than the second flow regulating cloth 345. In this case,
at the time of regulating the spacing distance of the first
regulating member 365, not the body 365 but the expanded flow
regulating cloth 363 regulates the flow of the inflating gas.
[0296] Specifically, the airbag 361A having the flow regulating
cloth 365 comprises the single flow regulating cloth 363 and the
two pairs of first and second regulating members 365a, 365b, 371
and 371 in the airbag 361A. The airbag 361 thus constructed cannot
regulate the flow of the inflating gas in two stages, differently
at the beginning of inflation and before the completion of
inflation, but can attain actions and effects similar to those of
the airbag 361. In this airbag 361A, moreover, the first and second
regulating members 365 and 371 are made of a continuous regulating
member 372A having flexibility. In this airbag 361A, therefore, it
is also possible to use the joints of the regulating member 372A to
the vehicle front-facing wall portion 22 and the passenger-facing
wall portion 25 to join two members. As compared with the case in
which the first and second regulating members are separately
arranged, therefore, it is possible to reduce the number of
components. Moreover, the works of joining the first and second
regulating members 365 and 371 can be simplified to reduce the
number of steps of and lower the cost for manufacturing the airbag
361A.
[0297] Here, the first and second regulating members may be
constructed into a regulating cloth material 372B, as indicated by
double-dotted lines in FIG. 23A, when they are made of a continuous
regulating member having flexibility. This regulating cloth
material 372B is provided with a tuck 372a with easily broken
sewing thread 373 at a portion between a vehicle front-facing joint
portion 368A and a passenger side joint portion 366A at the lower
and upper ends respectively when it is vertically elongated.
Moreover, the regulating cloth material 372B is the first
regulating member 365A before the sewing thread 373 is broken. By
the breakage of the first regulating member 365A with the breakage
of the sewing thread 373, the cloth material 372B is elongated and
becomes the second regulating member 371A.
[0298] Here, the fifth embodiment has been described on the airbag
device M5 for the steering wheel, but the invention may also be
applied to an airbag device for a passenger's seat.
[0299] An airbag device M6 of a sixth embodiment is provided for
the steering wheel and has a construction similar to that of the
foregoing airbag device M1 except for the airbag 420. Therefore,
common members are given the same reference numerals.
[0300] The airbag 420 is provided, as shown in FIG. 24, with an
airbag body 421 and a connecting member 436. Here, the airbag body
421 has a construction similar to that of the airbag body 21 of the
airbag 20 in the aforementioned airbag device M1. Therefore, the
description will be omitted by designating the common members by
the common reference numerals.
[0301] Like the airbag body 421, the connecting member 436 is made
of a woven fabric having flexibility such as polyamide or
polyester. The connecting member 436 is provided, as shown in FIG.
24, with a generally circular connecting portion main body 437, and
two band-shaped tether portions (or tethers) 443 and 443 extending
from the circumferential edge of the connecting portion main body
437. The connecting portion main body 437 is joined to the
passenger-facing wall portion 25 (or the passenger side base cloth
29) and to the vehicle front-facing wall portion 22 at the
periphery of the gas inlet port 23 in. In other words, the
connecting portion main body 437 connects the passenger-facing wall
portion 25 and the periphery of the gas inlet port 23. When the
internal pressure of the airbag body 421 reaches a predetermined
level, moreover, the connecting portion main body 437 separates
from the passenger-facing wall portion 25 and from the periphery of
the gas inlet port 23.
[0302] Specifically, the connecting portion main body 437 is joined
to the passenger-facing wall portion 25 by sewing it to the
passenger side base cloth 29 at an annular joint portion 438 (or
the sewing location 50) arranged near the outer circumferential
edge of the connecting portion main body 437. This joint portion
438 is so arranged that the center of its annular shape C2 is
offset by L1 to the front of the vehicle from the center of the
passenger side base cloth 29 (i.e., the axis of the center Cl of
the gas inlet port 23 in the body side base cloth 28), as shown in
FIG. 24, when it is expanded flat and the body side base cloth 28
and the passenger side base cloth 29 are superposed. In the inner
portion of the joint portion 438 in the connecting portion main
body 437, moreover, there is arranged a joint portion 439 joining
with the periphery of the gas inlet port 23. Like the airbag 20 in
the aforementioned airbag device M1, the joint portion 439 is
joined to the circumferential edge of the gas inlet port 23 by
using the retainer 6. The joint portion 439 is provided with a
circular opening 439a through which the inflator body 8a can pass,
and mounting holes 439b formed in the periphery of the opening 439a
for through which the bolts 6a of the retainer 6 can pass.
[0303] The opening 439a in the joint portion 439 is aligned at its
center with the center C2 of the joint portion 438 joining the
connecting portion main body 437 and the passenger side base cloth
29. When the airbag 420 is mounted and fixed on the (not-shown) bag
holder together with the retainer 6 to join the joint portion 439
to the vicinity of the gas inlet port 23, moreover, the center of
the joint portion 439 (or the center of the opening 439a) is
aligned with the center C1 of the gas inlet port 23. In the airbag
420 of the sixth embodiment, more specifically, when the airbag 420
is mounted and fixed on the bag holder together with the retainer
6, the length of the film in vertical cross section centering the
gas inlet port 23 in the airbag body 421, is longer in its rear
side portion 456 by L1 than in its front side portion 455 (FIG. 25
and FIG. 26A) This is because, in the airbag 420, the center C2 in
the joint portion 438 between the connecting portion main body 437
and the passenger side base cloth 29 is offset forward by L1 from
the center C1 in the joint portion 439 between the connecting
portion main body 437 and the periphery of the gas inlet port 23
(or the opening center of the gas inlet port 23).
[0304] In the connecting portion main body 437, on the other hand,
the gas outlet ports 40 for allowing the inflating gas discharged
from the inflator 8 to flow out into the airbag body 421, and the
easily torn portions 41 are arranged between the joint portions 438
and 439. These gas outlet ports 40 and easily torn portions 41 have
constructions similar to those of the gas outlet ports 40 and the
easily torn portions 41 in the airbag 20 in the aforementioned
airbag device M1. Therefore, common members are given the same
reference numerals. In short, the connecting portion body 437 acts
as the flow regulating member, too. When the easily torn portions
41 are torn, moreover, the joint portion 438 and the joint portion
439 in the connecting portion body 437 are separated so that the
passenger side base cloth 29 (or the passenger-facing wall portion
25) and the periphery of the gas inlet port 23 are
disconnected.
[0305] The tether portions 443 and 443 are formed in a band shape
and extended to protrude laterally from the circumferential edge of
the connecting portion main body 437. The tether portions 443
regulate, at the time of inflation of the airbag 420, the spacing
distance of the passenger-facing wall portion 25 from the gas inlet
port 23 and so regulate the inflated shape of the airbag body 421.
Moreover, the tether portions 443 are so offset (FIG. 24) rearward
from the center of the connecting portion main body 437 that their
center line extending left to right extends through the center C1
of the gas inlet port 23 when the airbag 420 is expanded flat.
[0306] The airbag 420 of the sixth embodiment can be manufactured
like the airbag 20 in the airbag device M1 of the first embodiment.
Moreover, the airbag 420 is folded longitudinally and laterally
with the retainer 6 arranged between the passenger side base cloth
29 and the connecting portion body 437.
[0307] Specifically, with the retainer 6 arranged inside the
airbag, as shown in FIG. 26A, the airbag 420 is expanded flat so
that the passenger side base cloth 29 is superposed over the body
side base cloth 28. At this time, the passenger side base cloth 29
and the body side base cloth 28 are arranged with a longitudinal
displacement. Then, the airbag body 421 is laid flat (FIGS. 25 and
26A) so that the length of the film of the rear side portion 456 is
longer than that of the front side portion 455. This is because the
joint portion 438 between the connecting portion body 437 and the
passenger side base cloth 29 has its center C2 offset forward in
the airbag body 421 (FIG. 24).
[0308] After this, as shown in FIGS. 26B and 26C, the right side
portion 458 of the airbag 420 is so folded at first with
longitudinal creases that it lies on the passenger side base cloth
29. Next, the left side portion 459 of the airbag 420 is so folded
with longitudinal creases that it lies on the right side portion
458. Specifically, the right side portion 458 and the left side
portion 459 are folded on each other over the gas inlet port 23
progressively superposing in a direction normal to the opening
plane L of the gas inlet port 23, thereby to arrange one folded
portion 460. At this time, the right-most edge portion 458a and the
left-most edge portion 459a of the right side portion 458 and the
left side portion 459 respectively are folded back toward the gas
inlet port 23 so that they are not exposed to the upper side, that
is, the passenger side.
[0309] Thereafter, the front side portion 462 and the rear side
portion 463 of a longitudinally folded airbag 461 are folded (as
referred to FIGS. 26C and 26D) with lateral creases so that the
edges approach the gas inlet port 23. In the case of the sixth
embodiment, the front side portion 462 and the rear side portion
463 are s folded in bellows form so that their end portions 462a
and 463a are on either side of the gas inlet port 23. In other
words, the front side portion 462 and the rear side portion 463 are
so folded as to form two folded portions 464 and 465 next to each
other and lined up in the longitudinal direction, as shown in FIG.
26D.
[0310] Moreover, the airbag 420 thus folded can be mounted on the
vehicle like the airbag 20 in the airbag device M1.
[0311] In the airbag device M6 of the sixth embodiment, the airbag
body 421 is formed by sewing the circumferential edges of the body
side base cloth 28 and the passenger side base cloth 29, which are
given generally identical contours. With the body side base cloth
28 and the passenger side base cloth 29 laid flat over each other,
moreover, the joint portion 438 joining the connecting member 436
and the passenger-facing wall portion 25 (or the passenger side
base cloth 29) is arranged such that the its center C2 is offset by
L1 from the center C1 of the joint portion 439 joining the
connecting member 436 and the vicinity of the circumferential edge
of the gas inlet port 23 (FIG. 24).
[0312] Therefore, the vertical cross section through the gas inlet
port 23 in the airbag body 421 has the following film length. The
length of the film of the vehicle front-facing (forward) portion
455 of the airbag body 421 in the offset direction of the center C2
of the joint portion 438 joining the connecting member 436 and the
passenger side base cloth 29 is shorter by the offset L1 than that
of the vehicle rear-facing (rearward) portion 456 opposite to the
offset direction. In other words, the length of the film of the
rearward portion 456 of the airbag body 421 opposite the offset
direction of the center C2 of the joint portion 438 joining the
connecting member 436 and the passenger side base cloth 29 can be
elongated by the offset L1 (FIG. 25).
[0313] In the airbag device M6 of the sixth embodiment, moreover,
the airbag body 421 begins to inflate at first with the passenger
side base cloth 29 and the vicinity of the gas inlet port 23 being
connected by the connecting member 436. At the beginning of
inflation of the airbag 420, therefore, the airbag 420 can be
inflated, as indicated by double-dotted lines in FIG. 25, to
enlarge the depth of the rearward portion 456 of the airbag body
421 which is then enlarged in the film depth in the area opposite
the offset direction of the center C2 of the joint portion 438
joining the connecting member 436 and the passenger side base cloth
29. In the airbag device M6 of the sixth embodiment, in other
words, the center C2 of the joint portion 438 joining the
connecting member 436 and the passenger side base cloth 29 is
offset in the opposite direction from center of the portion of the
airbag body 421 which is desired to be promptly expanded (in this
case the rear side portion 456). Therefore, the airbag 420 can be
so promptly inflated at the beginning as to retain the cushioning
effect by expanding the rearward portion 456 quickly.
[0314] In the airbag device M6 of the sixth embodiment, on the
other hand, the connecting member 436 connects the passenger side
base cloth 29 and the periphery of the gas inlet port 23 of the
airbag body 421. At the beginning of inflation of the airbag 420,
therefore, the airbag body 421 is prevented from protruding toward
the driver. At the beginning of inflation of the airbag 420, more
specifically, the inflating gas flows toward the portion around the
gas inlet port 23 of the airbag body 421 to promote the inflation
of the portion around the gas inlet port 23 of the airbag body 421.
When the inflating gas further flows into the airbag body 421 so
that the internal pressure of the airbag body 421 reaches a
predetermined level, moreover, the portions 41 and 41 in the
connecting portion body 437 are broken. Then, the passenger side
base cloth 29 and the vicinity of the gas inlet port 23 are
disconnected so that the airbag body 421 can complete its
inflation.
[0315] In the airbag device M6 of the sixth embodiment, therefore,
the predetermined portion around the gas inlet port 23 of the
airbag 420 at the beginning of inflation can be quickly inflated
deeply to protect the driver properly.
[0316] In the airbag device M6 of the sixth embodiment, moreover,
the offset direction of the center C2 of the joint portion 438
joining the connecting member 436 and the passenger side base cloth
29 is shifted forward. At the beginning of inflation, therefore,
the airbag 420 can be inflated to first enlarge the depth of the
rearward portion 456 in the airbag body 421. In other words, the
rearward portion 456 is quickly inflated so that the depth there is
increased quickly while the airbag is prevented from protruding
toward the driver. As a result, the airbag 420 can be quickly
inflated between the ring portion of the steering wheel and the
abdomen of the driver, with sufficient depth to protect the abdomen
properly at the beginning of inflation of the airbag 420.
[0317] In the airbag device M6 of the sixth embodiment, moreover,
the gas outlet ports 40 and 40 are so arranged that the connecting
portion main body 437 of the connecting member 436 may act as the
flow regulating member. Therefore, the connecting portion main body
437 performs actions similar to those of the flow regulating cloth
body 37 in the airbag device M1 of the first embodiment. In the
airbag device M6 of the sixth embodiment, on the other hand, the
tethers 443 and 443 are integrated with the connecting member 436
so that no separate tether need be added, and it is possible to
reduce the number of steps of and lower the cost for manufacturing
the airbag 420.
[0318] In the airbag device M6 such that the edge portions 458a and
459a of the right side portion 458 and the left side portion 459
are folded back to the gas inlet port 23. When the right side
portion 458 and the left side portion 459 are unfolded at the time
of expanding and inflating the airbag 420, their right-most edge
portion 458a and left-most edge portion 459a are difficult to open
toward the driver so that the airbag 420 can be widely expanded
while being prevented from protruding to the driver.
* * * * *